1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/lib/vsprintf.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 /*
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
11 */
12
13 /*
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
18 */
19
20 #include <stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/time.h>
38 #include <linux/uuid.h>
39 #include <linux/of.h>
40 #include <net/addrconf.h>
41 #include <linux/siphash.h>
42 #include <linux/compiler.h>
43 #include <linux/property.h>
44 #ifdef CONFIG_BLOCK
45 #include <linux/blkdev.h>
46 #endif
47
48 #include "../mm/internal.h" /* For the trace_print_flags arrays */
49
50 #include <asm/page.h> /* for PAGE_SIZE */
51 #include <asm/byteorder.h> /* cpu_to_le16 */
52
53 #include <linux/string_helpers.h>
54 #include "kstrtox.h"
55
simple_strntoull(const char * startp,size_t max_chars,char ** endp,unsigned int base)56 static unsigned long long simple_strntoull(const char *startp, size_t max_chars,
57 char **endp, unsigned int base)
58 {
59 const char *cp;
60 unsigned long long result = 0ULL;
61 size_t prefix_chars;
62 unsigned int rv;
63
64 cp = _parse_integer_fixup_radix(startp, &base);
65 prefix_chars = cp - startp;
66 if (prefix_chars < max_chars) {
67 rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars);
68 /* FIXME */
69 cp += (rv & ~KSTRTOX_OVERFLOW);
70 } else {
71 /* Field too short for prefix + digit, skip over without converting */
72 cp = startp + max_chars;
73 }
74
75 if (endp)
76 *endp = (char *)cp;
77
78 return result;
79 }
80
81 /**
82 * simple_strtoull - convert a string to an unsigned long long
83 * @cp: The start of the string
84 * @endp: A pointer to the end of the parsed string will be placed here
85 * @base: The number base to use
86 *
87 * This function has caveats. Please use kstrtoull instead.
88 */
simple_strtoull(const char * cp,char ** endp,unsigned int base)89 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
90 {
91 return simple_strntoull(cp, INT_MAX, endp, base);
92 }
93 EXPORT_SYMBOL(simple_strtoull);
94
95 /**
96 * simple_strtoul - convert a string to an unsigned long
97 * @cp: The start of the string
98 * @endp: A pointer to the end of the parsed string will be placed here
99 * @base: The number base to use
100 *
101 * This function has caveats. Please use kstrtoul instead.
102 */
simple_strtoul(const char * cp,char ** endp,unsigned int base)103 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
104 {
105 return simple_strtoull(cp, endp, base);
106 }
107 EXPORT_SYMBOL(simple_strtoul);
108
109 /**
110 * simple_strtol - convert a string to a signed long
111 * @cp: The start of the string
112 * @endp: A pointer to the end of the parsed string will be placed here
113 * @base: The number base to use
114 *
115 * This function has caveats. Please use kstrtol instead.
116 */
simple_strtol(const char * cp,char ** endp,unsigned int base)117 long simple_strtol(const char *cp, char **endp, unsigned int base)
118 {
119 if (*cp == '-')
120 return -simple_strtoul(cp + 1, endp, base);
121
122 return simple_strtoul(cp, endp, base);
123 }
124 EXPORT_SYMBOL(simple_strtol);
125
simple_strntoll(const char * cp,size_t max_chars,char ** endp,unsigned int base)126 static long long simple_strntoll(const char *cp, size_t max_chars, char **endp,
127 unsigned int base)
128 {
129 /*
130 * simple_strntoull() safely handles receiving max_chars==0 in the
131 * case cp[0] == '-' && max_chars == 1.
132 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
133 * and the content of *cp is irrelevant.
134 */
135 if (*cp == '-' && max_chars > 0)
136 return -simple_strntoull(cp + 1, max_chars - 1, endp, base);
137
138 return simple_strntoull(cp, max_chars, endp, base);
139 }
140
141 /**
142 * simple_strtoll - convert a string to a signed long long
143 * @cp: The start of the string
144 * @endp: A pointer to the end of the parsed string will be placed here
145 * @base: The number base to use
146 *
147 * This function has caveats. Please use kstrtoll instead.
148 */
simple_strtoll(const char * cp,char ** endp,unsigned int base)149 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
150 {
151 return simple_strntoll(cp, INT_MAX, endp, base);
152 }
153 EXPORT_SYMBOL(simple_strtoll);
154
155 static noinline_for_stack
skip_atoi(const char ** s)156 int skip_atoi(const char **s)
157 {
158 int i = 0;
159
160 do {
161 i = i*10 + *((*s)++) - '0';
162 } while (isdigit(**s));
163
164 return i;
165 }
166
167 /*
168 * Decimal conversion is by far the most typical, and is used for
169 * /proc and /sys data. This directly impacts e.g. top performance
170 * with many processes running. We optimize it for speed by emitting
171 * two characters at a time, using a 200 byte lookup table. This
172 * roughly halves the number of multiplications compared to computing
173 * the digits one at a time. Implementation strongly inspired by the
174 * previous version, which in turn used ideas described at
175 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
176 * from the author, Douglas W. Jones).
177 *
178 * It turns out there is precisely one 26 bit fixed-point
179 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
180 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
181 * range happens to be somewhat larger (x <= 1073741898), but that's
182 * irrelevant for our purpose.
183 *
184 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
185 * need a 32x32->64 bit multiply, so we simply use the same constant.
186 *
187 * For dividing a number in the range [100, 10^4-1] by 100, there are
188 * several options. The simplest is (x * 0x147b) >> 19, which is valid
189 * for all x <= 43698.
190 */
191
192 static const u16 decpair[100] = {
193 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
194 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
195 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
196 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
197 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
198 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
199 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
200 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
201 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
202 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
203 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
204 #undef _
205 };
206
207 /*
208 * This will print a single '0' even if r == 0, since we would
209 * immediately jump to out_r where two 0s would be written but only
210 * one of them accounted for in buf. This is needed by ip4_string
211 * below. All other callers pass a non-zero value of r.
212 */
213 static noinline_for_stack
put_dec_trunc8(char * buf,unsigned r)214 char *put_dec_trunc8(char *buf, unsigned r)
215 {
216 unsigned q;
217
218 /* 1 <= r < 10^8 */
219 if (r < 100)
220 goto out_r;
221
222 /* 100 <= r < 10^8 */
223 q = (r * (u64)0x28f5c29) >> 32;
224 *((u16 *)buf) = decpair[r - 100*q];
225 buf += 2;
226
227 /* 1 <= q < 10^6 */
228 if (q < 100)
229 goto out_q;
230
231 /* 100 <= q < 10^6 */
232 r = (q * (u64)0x28f5c29) >> 32;
233 *((u16 *)buf) = decpair[q - 100*r];
234 buf += 2;
235
236 /* 1 <= r < 10^4 */
237 if (r < 100)
238 goto out_r;
239
240 /* 100 <= r < 10^4 */
241 q = (r * 0x147b) >> 19;
242 *((u16 *)buf) = decpair[r - 100*q];
243 buf += 2;
244 out_q:
245 /* 1 <= q < 100 */
246 r = q;
247 out_r:
248 /* 1 <= r < 100 */
249 *((u16 *)buf) = decpair[r];
250 buf += r < 10 ? 1 : 2;
251 return buf;
252 }
253
254 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
255 static noinline_for_stack
put_dec_full8(char * buf,unsigned r)256 char *put_dec_full8(char *buf, unsigned r)
257 {
258 unsigned q;
259
260 /* 0 <= r < 10^8 */
261 q = (r * (u64)0x28f5c29) >> 32;
262 *((u16 *)buf) = decpair[r - 100*q];
263 buf += 2;
264
265 /* 0 <= q < 10^6 */
266 r = (q * (u64)0x28f5c29) >> 32;
267 *((u16 *)buf) = decpair[q - 100*r];
268 buf += 2;
269
270 /* 0 <= r < 10^4 */
271 q = (r * 0x147b) >> 19;
272 *((u16 *)buf) = decpair[r - 100*q];
273 buf += 2;
274
275 /* 0 <= q < 100 */
276 *((u16 *)buf) = decpair[q];
277 buf += 2;
278 return buf;
279 }
280
281 static noinline_for_stack
put_dec(char * buf,unsigned long long n)282 char *put_dec(char *buf, unsigned long long n)
283 {
284 if (n >= 100*1000*1000)
285 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
286 /* 1 <= n <= 1.6e11 */
287 if (n >= 100*1000*1000)
288 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
289 /* 1 <= n < 1e8 */
290 return put_dec_trunc8(buf, n);
291 }
292
293 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
294
295 static void
put_dec_full4(char * buf,unsigned r)296 put_dec_full4(char *buf, unsigned r)
297 {
298 unsigned q;
299
300 /* 0 <= r < 10^4 */
301 q = (r * 0x147b) >> 19;
302 *((u16 *)buf) = decpair[r - 100*q];
303 buf += 2;
304 /* 0 <= q < 100 */
305 *((u16 *)buf) = decpair[q];
306 }
307
308 /*
309 * Call put_dec_full4 on x % 10000, return x / 10000.
310 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
311 * holds for all x < 1,128,869,999. The largest value this
312 * helper will ever be asked to convert is 1,125,520,955.
313 * (second call in the put_dec code, assuming n is all-ones).
314 */
315 static noinline_for_stack
put_dec_helper4(char * buf,unsigned x)316 unsigned put_dec_helper4(char *buf, unsigned x)
317 {
318 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
319
320 put_dec_full4(buf, x - q * 10000);
321 return q;
322 }
323
324 /* Based on code by Douglas W. Jones found at
325 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
326 * (with permission from the author).
327 * Performs no 64-bit division and hence should be fast on 32-bit machines.
328 */
329 static
put_dec(char * buf,unsigned long long n)330 char *put_dec(char *buf, unsigned long long n)
331 {
332 uint32_t d3, d2, d1, q, h;
333
334 if (n < 100*1000*1000)
335 return put_dec_trunc8(buf, n);
336
337 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
338 h = (n >> 32);
339 d2 = (h ) & 0xffff;
340 d3 = (h >> 16); /* implicit "& 0xffff" */
341
342 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
343 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
344 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
345 q = put_dec_helper4(buf, q);
346
347 q += 7671 * d3 + 9496 * d2 + 6 * d1;
348 q = put_dec_helper4(buf+4, q);
349
350 q += 4749 * d3 + 42 * d2;
351 q = put_dec_helper4(buf+8, q);
352
353 q += 281 * d3;
354 buf += 12;
355 if (q)
356 buf = put_dec_trunc8(buf, q);
357 else while (buf[-1] == '0')
358 --buf;
359
360 return buf;
361 }
362
363 #endif
364
365 /*
366 * Convert passed number to decimal string.
367 * Returns the length of string. On buffer overflow, returns 0.
368 *
369 * If speed is not important, use snprintf(). It's easy to read the code.
370 */
num_to_str(char * buf,int size,unsigned long long num,unsigned int width)371 int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
372 {
373 /* put_dec requires 2-byte alignment of the buffer. */
374 char tmp[sizeof(num) * 3] __aligned(2);
375 int idx, len;
376
377 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
378 if (num <= 9) {
379 tmp[0] = '0' + num;
380 len = 1;
381 } else {
382 len = put_dec(tmp, num) - tmp;
383 }
384
385 if (len > size || width > size)
386 return 0;
387
388 if (width > len) {
389 width = width - len;
390 for (idx = 0; idx < width; idx++)
391 buf[idx] = ' ';
392 } else {
393 width = 0;
394 }
395
396 for (idx = 0; idx < len; ++idx)
397 buf[idx + width] = tmp[len - idx - 1];
398
399 return len + width;
400 }
401
402 #define SIGN 1 /* unsigned/signed, must be 1 */
403 #define LEFT 2 /* left justified */
404 #define PLUS 4 /* show plus */
405 #define SPACE 8 /* space if plus */
406 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
407 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
408 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
409
410 static_assert(ZEROPAD == ('0' - ' '));
411 static_assert(SMALL == ' ');
412
413 enum format_type {
414 FORMAT_TYPE_NONE, /* Just a string part */
415 FORMAT_TYPE_WIDTH,
416 FORMAT_TYPE_PRECISION,
417 FORMAT_TYPE_CHAR,
418 FORMAT_TYPE_STR,
419 FORMAT_TYPE_PTR,
420 FORMAT_TYPE_PERCENT_CHAR,
421 FORMAT_TYPE_INVALID,
422 FORMAT_TYPE_LONG_LONG,
423 FORMAT_TYPE_ULONG,
424 FORMAT_TYPE_LONG,
425 FORMAT_TYPE_UBYTE,
426 FORMAT_TYPE_BYTE,
427 FORMAT_TYPE_USHORT,
428 FORMAT_TYPE_SHORT,
429 FORMAT_TYPE_UINT,
430 FORMAT_TYPE_INT,
431 FORMAT_TYPE_SIZE_T,
432 FORMAT_TYPE_PTRDIFF
433 };
434
435 struct printf_spec {
436 unsigned int type:8; /* format_type enum */
437 signed int field_width:24; /* width of output field */
438 unsigned int flags:8; /* flags to number() */
439 unsigned int base:8; /* number base, 8, 10 or 16 only */
440 signed int precision:16; /* # of digits/chars */
441 } __packed;
442 static_assert(sizeof(struct printf_spec) == 8);
443
444 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
445 #define PRECISION_MAX ((1 << 15) - 1)
446
447 static noinline_for_stack
number(char * buf,char * end,unsigned long long num,struct printf_spec spec)448 char *number(char *buf, char *end, unsigned long long num,
449 struct printf_spec spec)
450 {
451 /* put_dec requires 2-byte alignment of the buffer. */
452 char tmp[3 * sizeof(num)] __aligned(2);
453 char sign;
454 char locase;
455 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
456 int i;
457 bool is_zero = num == 0LL;
458 int field_width = spec.field_width;
459 int precision = spec.precision;
460
461 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
462 * produces same digits or (maybe lowercased) letters */
463 locase = (spec.flags & SMALL);
464 if (spec.flags & LEFT)
465 spec.flags &= ~ZEROPAD;
466 sign = 0;
467 if (spec.flags & SIGN) {
468 if ((signed long long)num < 0) {
469 sign = '-';
470 num = -(signed long long)num;
471 field_width--;
472 } else if (spec.flags & PLUS) {
473 sign = '+';
474 field_width--;
475 } else if (spec.flags & SPACE) {
476 sign = ' ';
477 field_width--;
478 }
479 }
480 if (need_pfx) {
481 if (spec.base == 16)
482 field_width -= 2;
483 else if (!is_zero)
484 field_width--;
485 }
486
487 /* generate full string in tmp[], in reverse order */
488 i = 0;
489 if (num < spec.base)
490 tmp[i++] = hex_asc_upper[num] | locase;
491 else if (spec.base != 10) { /* 8 or 16 */
492 int mask = spec.base - 1;
493 int shift = 3;
494
495 if (spec.base == 16)
496 shift = 4;
497 do {
498 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
499 num >>= shift;
500 } while (num);
501 } else { /* base 10 */
502 i = put_dec(tmp, num) - tmp;
503 }
504
505 /* printing 100 using %2d gives "100", not "00" */
506 if (i > precision)
507 precision = i;
508 /* leading space padding */
509 field_width -= precision;
510 if (!(spec.flags & (ZEROPAD | LEFT))) {
511 while (--field_width >= 0) {
512 if (buf < end)
513 *buf = ' ';
514 ++buf;
515 }
516 }
517 /* sign */
518 if (sign) {
519 if (buf < end)
520 *buf = sign;
521 ++buf;
522 }
523 /* "0x" / "0" prefix */
524 if (need_pfx) {
525 if (spec.base == 16 || !is_zero) {
526 if (buf < end)
527 *buf = '0';
528 ++buf;
529 }
530 if (spec.base == 16) {
531 if (buf < end)
532 *buf = ('X' | locase);
533 ++buf;
534 }
535 }
536 /* zero or space padding */
537 if (!(spec.flags & LEFT)) {
538 char c = ' ' + (spec.flags & ZEROPAD);
539
540 while (--field_width >= 0) {
541 if (buf < end)
542 *buf = c;
543 ++buf;
544 }
545 }
546 /* hmm even more zero padding? */
547 while (i <= --precision) {
548 if (buf < end)
549 *buf = '0';
550 ++buf;
551 }
552 /* actual digits of result */
553 while (--i >= 0) {
554 if (buf < end)
555 *buf = tmp[i];
556 ++buf;
557 }
558 /* trailing space padding */
559 while (--field_width >= 0) {
560 if (buf < end)
561 *buf = ' ';
562 ++buf;
563 }
564
565 return buf;
566 }
567
568 static noinline_for_stack
special_hex_number(char * buf,char * end,unsigned long long num,int size)569 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
570 {
571 struct printf_spec spec;
572
573 spec.type = FORMAT_TYPE_PTR;
574 spec.field_width = 2 + 2 * size; /* 0x + hex */
575 spec.flags = SPECIAL | SMALL | ZEROPAD;
576 spec.base = 16;
577 spec.precision = -1;
578
579 return number(buf, end, num, spec);
580 }
581
move_right(char * buf,char * end,unsigned len,unsigned spaces)582 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
583 {
584 size_t size;
585 if (buf >= end) /* nowhere to put anything */
586 return;
587 size = end - buf;
588 if (size <= spaces) {
589 memset(buf, ' ', size);
590 return;
591 }
592 if (len) {
593 if (len > size - spaces)
594 len = size - spaces;
595 memmove(buf + spaces, buf, len);
596 }
597 memset(buf, ' ', spaces);
598 }
599
600 /*
601 * Handle field width padding for a string.
602 * @buf: current buffer position
603 * @n: length of string
604 * @end: end of output buffer
605 * @spec: for field width and flags
606 * Returns: new buffer position after padding.
607 */
608 static noinline_for_stack
widen_string(char * buf,int n,char * end,struct printf_spec spec)609 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
610 {
611 unsigned spaces;
612
613 if (likely(n >= spec.field_width))
614 return buf;
615 /* we want to pad the sucker */
616 spaces = spec.field_width - n;
617 if (!(spec.flags & LEFT)) {
618 move_right(buf - n, end, n, spaces);
619 return buf + spaces;
620 }
621 while (spaces--) {
622 if (buf < end)
623 *buf = ' ';
624 ++buf;
625 }
626 return buf;
627 }
628
629 /* Handle string from a well known address. */
string_nocheck(char * buf,char * end,const char * s,struct printf_spec spec)630 static char *string_nocheck(char *buf, char *end, const char *s,
631 struct printf_spec spec)
632 {
633 int len = 0;
634 int lim = spec.precision;
635
636 while (lim--) {
637 char c = *s++;
638 if (!c)
639 break;
640 if (buf < end)
641 *buf = c;
642 ++buf;
643 ++len;
644 }
645 return widen_string(buf, len, end, spec);
646 }
647
err_ptr(char * buf,char * end,void * ptr,struct printf_spec spec)648 static char *err_ptr(char *buf, char *end, void *ptr,
649 struct printf_spec spec)
650 {
651 int err = PTR_ERR(ptr);
652 const char *sym = errname(err);
653
654 if (sym)
655 return string_nocheck(buf, end, sym, spec);
656
657 /*
658 * Somebody passed ERR_PTR(-1234) or some other non-existing
659 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
660 * printing it as its decimal representation.
661 */
662 spec.flags |= SIGN;
663 spec.base = 10;
664 return number(buf, end, err, spec);
665 }
666
667 /* Be careful: error messages must fit into the given buffer. */
error_string(char * buf,char * end,const char * s,struct printf_spec spec)668 static char *error_string(char *buf, char *end, const char *s,
669 struct printf_spec spec)
670 {
671 /*
672 * Hard limit to avoid a completely insane messages. It actually
673 * works pretty well because most error messages are in
674 * the many pointer format modifiers.
675 */
676 if (spec.precision == -1)
677 spec.precision = 2 * sizeof(void *);
678
679 return string_nocheck(buf, end, s, spec);
680 }
681
682 /*
683 * Do not call any complex external code here. Nested printk()/vsprintf()
684 * might cause infinite loops. Failures might break printk() and would
685 * be hard to debug.
686 */
check_pointer_msg(const void * ptr)687 static const char *check_pointer_msg(const void *ptr)
688 {
689 if (!ptr)
690 return "(null)";
691
692 if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
693 return "(efault)";
694
695 return NULL;
696 }
697
check_pointer(char ** buf,char * end,const void * ptr,struct printf_spec spec)698 static int check_pointer(char **buf, char *end, const void *ptr,
699 struct printf_spec spec)
700 {
701 const char *err_msg;
702
703 err_msg = check_pointer_msg(ptr);
704 if (err_msg) {
705 *buf = error_string(*buf, end, err_msg, spec);
706 return -EFAULT;
707 }
708
709 return 0;
710 }
711
712 static noinline_for_stack
string(char * buf,char * end,const char * s,struct printf_spec spec)713 char *string(char *buf, char *end, const char *s,
714 struct printf_spec spec)
715 {
716 if (check_pointer(&buf, end, s, spec))
717 return buf;
718
719 return string_nocheck(buf, end, s, spec);
720 }
721
pointer_string(char * buf,char * end,const void * ptr,struct printf_spec spec)722 static char *pointer_string(char *buf, char *end,
723 const void *ptr,
724 struct printf_spec spec)
725 {
726 spec.base = 16;
727 spec.flags |= SMALL;
728 if (spec.field_width == -1) {
729 spec.field_width = 2 * sizeof(ptr);
730 spec.flags |= ZEROPAD;
731 }
732
733 return number(buf, end, (unsigned long int)ptr, spec);
734 }
735
736 /* Make pointers available for printing early in the boot sequence. */
737 static int debug_boot_weak_hash __ro_after_init;
738
debug_boot_weak_hash_enable(char * str)739 static int __init debug_boot_weak_hash_enable(char *str)
740 {
741 debug_boot_weak_hash = 1;
742 pr_info("debug_boot_weak_hash enabled\n");
743 return 0;
744 }
745 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
746
747 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key);
748 static siphash_key_t ptr_key __read_mostly;
749
enable_ptr_key_workfn(struct work_struct * work)750 static void enable_ptr_key_workfn(struct work_struct *work)
751 {
752 get_random_bytes(&ptr_key, sizeof(ptr_key));
753 /* Needs to run from preemptible context */
754 static_branch_disable(¬_filled_random_ptr_key);
755 }
756
757 static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
758
fill_random_ptr_key(struct notifier_block * nb,unsigned long action,void * data)759 static int fill_random_ptr_key(struct notifier_block *nb,
760 unsigned long action, void *data)
761 {
762 /* This may be in an interrupt handler. */
763 queue_work(system_unbound_wq, &enable_ptr_key_work);
764 return 0;
765 }
766
767 static struct notifier_block random_ready = {
768 .notifier_call = fill_random_ptr_key
769 };
770
initialize_ptr_random(void)771 static int __init initialize_ptr_random(void)
772 {
773 int key_size = sizeof(ptr_key);
774 int ret;
775
776 /* Use hw RNG if available. */
777 if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
778 static_branch_disable(¬_filled_random_ptr_key);
779 return 0;
780 }
781
782 ret = register_random_ready_notifier(&random_ready);
783 if (!ret) {
784 return 0;
785 } else if (ret == -EALREADY) {
786 /* This is in preemptible context */
787 enable_ptr_key_workfn(&enable_ptr_key_work);
788 return 0;
789 }
790
791 return ret;
792 }
793 early_initcall(initialize_ptr_random);
794
795 /* Maps a pointer to a 32 bit unique identifier. */
__ptr_to_hashval(const void * ptr,unsigned long * hashval_out)796 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
797 {
798 unsigned long hashval;
799
800 if (static_branch_unlikely(¬_filled_random_ptr_key))
801 return -EAGAIN;
802
803 #ifdef CONFIG_64BIT
804 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
805 /*
806 * Mask off the first 32 bits, this makes explicit that we have
807 * modified the address (and 32 bits is plenty for a unique ID).
808 */
809 hashval = hashval & 0xffffffff;
810 #else
811 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
812 #endif
813 *hashval_out = hashval;
814 return 0;
815 }
816
ptr_to_hashval(const void * ptr,unsigned long * hashval_out)817 int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
818 {
819 return __ptr_to_hashval(ptr, hashval_out);
820 }
821
ptr_to_id(char * buf,char * end,const void * ptr,struct printf_spec spec)822 static char *ptr_to_id(char *buf, char *end, const void *ptr,
823 struct printf_spec spec)
824 {
825 const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
826 unsigned long hashval;
827 int ret;
828
829 /*
830 * Print the real pointer value for NULL and error pointers,
831 * as they are not actual addresses.
832 */
833 if (IS_ERR_OR_NULL(ptr))
834 return pointer_string(buf, end, ptr, spec);
835
836 /* When debugging early boot use non-cryptographically secure hash. */
837 if (unlikely(debug_boot_weak_hash)) {
838 hashval = hash_long((unsigned long)ptr, 32);
839 return pointer_string(buf, end, (const void *)hashval, spec);
840 }
841
842 ret = __ptr_to_hashval(ptr, &hashval);
843 if (ret) {
844 spec.field_width = 2 * sizeof(ptr);
845 /* string length must be less than default_width */
846 return error_string(buf, end, str, spec);
847 }
848
849 return pointer_string(buf, end, (const void *)hashval, spec);
850 }
851
852 int kptr_restrict __read_mostly;
853
854 static noinline_for_stack
restricted_pointer(char * buf,char * end,const void * ptr,struct printf_spec spec)855 char *restricted_pointer(char *buf, char *end, const void *ptr,
856 struct printf_spec spec)
857 {
858 switch (kptr_restrict) {
859 case 0:
860 /* Handle as %p, hash and do _not_ leak addresses. */
861 return ptr_to_id(buf, end, ptr, spec);
862 case 1: {
863 const struct cred *cred;
864
865 /*
866 * kptr_restrict==1 cannot be used in IRQ context
867 * because its test for CAP_SYSLOG would be meaningless.
868 */
869 if (in_irq() || in_serving_softirq() || in_nmi()) {
870 if (spec.field_width == -1)
871 spec.field_width = 2 * sizeof(ptr);
872 return error_string(buf, end, "pK-error", spec);
873 }
874
875 /*
876 * Only print the real pointer value if the current
877 * process has CAP_SYSLOG and is running with the
878 * same credentials it started with. This is because
879 * access to files is checked at open() time, but %pK
880 * checks permission at read() time. We don't want to
881 * leak pointer values if a binary opens a file using
882 * %pK and then elevates privileges before reading it.
883 */
884 cred = current_cred();
885 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
886 !uid_eq(cred->euid, cred->uid) ||
887 !gid_eq(cred->egid, cred->gid))
888 ptr = NULL;
889 break;
890 }
891 case 2:
892 default:
893 /* Always print 0's for %pK */
894 ptr = NULL;
895 break;
896 }
897
898 return pointer_string(buf, end, ptr, spec);
899 }
900
901 static noinline_for_stack
dentry_name(char * buf,char * end,const struct dentry * d,struct printf_spec spec,const char * fmt)902 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
903 const char *fmt)
904 {
905 const char *array[4], *s;
906 const struct dentry *p;
907 int depth;
908 int i, n;
909
910 switch (fmt[1]) {
911 case '2': case '3': case '4':
912 depth = fmt[1] - '0';
913 break;
914 default:
915 depth = 1;
916 }
917
918 rcu_read_lock();
919 for (i = 0; i < depth; i++, d = p) {
920 if (check_pointer(&buf, end, d, spec)) {
921 rcu_read_unlock();
922 return buf;
923 }
924
925 p = READ_ONCE(d->d_parent);
926 array[i] = READ_ONCE(d->d_name.name);
927 if (p == d) {
928 if (i)
929 array[i] = "";
930 i++;
931 break;
932 }
933 }
934 s = array[--i];
935 for (n = 0; n != spec.precision; n++, buf++) {
936 char c = *s++;
937 if (!c) {
938 if (!i)
939 break;
940 c = '/';
941 s = array[--i];
942 }
943 if (buf < end)
944 *buf = c;
945 }
946 rcu_read_unlock();
947 return widen_string(buf, n, end, spec);
948 }
949
950 static noinline_for_stack
file_dentry_name(char * buf,char * end,const struct file * f,struct printf_spec spec,const char * fmt)951 char *file_dentry_name(char *buf, char *end, const struct file *f,
952 struct printf_spec spec, const char *fmt)
953 {
954 if (check_pointer(&buf, end, f, spec))
955 return buf;
956
957 return dentry_name(buf, end, f->f_path.dentry, spec, fmt);
958 }
959 #ifdef CONFIG_BLOCK
960 static noinline_for_stack
bdev_name(char * buf,char * end,struct block_device * bdev,struct printf_spec spec,const char * fmt)961 char *bdev_name(char *buf, char *end, struct block_device *bdev,
962 struct printf_spec spec, const char *fmt)
963 {
964 struct gendisk *hd;
965
966 if (check_pointer(&buf, end, bdev, spec))
967 return buf;
968
969 hd = bdev->bd_disk;
970 buf = string(buf, end, hd->disk_name, spec);
971 if (bdev->bd_partno) {
972 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
973 if (buf < end)
974 *buf = 'p';
975 buf++;
976 }
977 buf = number(buf, end, bdev->bd_partno, spec);
978 }
979 return buf;
980 }
981 #endif
982
983 static noinline_for_stack
symbol_string(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)984 char *symbol_string(char *buf, char *end, void *ptr,
985 struct printf_spec spec, const char *fmt)
986 {
987 unsigned long value;
988 #ifdef CONFIG_KALLSYMS
989 char sym[KSYM_SYMBOL_LEN];
990 #endif
991
992 if (fmt[1] == 'R')
993 ptr = __builtin_extract_return_addr(ptr);
994 value = (unsigned long)ptr;
995
996 #ifdef CONFIG_KALLSYMS
997 if (*fmt == 'B')
998 sprint_backtrace(sym, value);
999 else if (*fmt != 's')
1000 sprint_symbol(sym, value);
1001 else
1002 sprint_symbol_no_offset(sym, value);
1003
1004 return string_nocheck(buf, end, sym, spec);
1005 #else
1006 return special_hex_number(buf, end, value, sizeof(void *));
1007 #endif
1008 }
1009
1010 static const struct printf_spec default_str_spec = {
1011 .field_width = -1,
1012 .precision = -1,
1013 };
1014
1015 static const struct printf_spec default_flag_spec = {
1016 .base = 16,
1017 .precision = -1,
1018 .flags = SPECIAL | SMALL,
1019 };
1020
1021 static const struct printf_spec default_dec_spec = {
1022 .base = 10,
1023 .precision = -1,
1024 };
1025
1026 static const struct printf_spec default_dec02_spec = {
1027 .base = 10,
1028 .field_width = 2,
1029 .precision = -1,
1030 .flags = ZEROPAD,
1031 };
1032
1033 static const struct printf_spec default_dec04_spec = {
1034 .base = 10,
1035 .field_width = 4,
1036 .precision = -1,
1037 .flags = ZEROPAD,
1038 };
1039
1040 static noinline_for_stack
resource_string(char * buf,char * end,struct resource * res,struct printf_spec spec,const char * fmt)1041 char *resource_string(char *buf, char *end, struct resource *res,
1042 struct printf_spec spec, const char *fmt)
1043 {
1044 #ifndef IO_RSRC_PRINTK_SIZE
1045 #define IO_RSRC_PRINTK_SIZE 6
1046 #endif
1047
1048 #ifndef MEM_RSRC_PRINTK_SIZE
1049 #define MEM_RSRC_PRINTK_SIZE 10
1050 #endif
1051 static const struct printf_spec io_spec = {
1052 .base = 16,
1053 .field_width = IO_RSRC_PRINTK_SIZE,
1054 .precision = -1,
1055 .flags = SPECIAL | SMALL | ZEROPAD,
1056 };
1057 static const struct printf_spec mem_spec = {
1058 .base = 16,
1059 .field_width = MEM_RSRC_PRINTK_SIZE,
1060 .precision = -1,
1061 .flags = SPECIAL | SMALL | ZEROPAD,
1062 };
1063 static const struct printf_spec bus_spec = {
1064 .base = 16,
1065 .field_width = 2,
1066 .precision = -1,
1067 .flags = SMALL | ZEROPAD,
1068 };
1069 static const struct printf_spec str_spec = {
1070 .field_width = -1,
1071 .precision = 10,
1072 .flags = LEFT,
1073 };
1074
1075 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1076 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1077 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1078 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1079 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1080 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1081 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
1082 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
1083
1084 char *p = sym, *pend = sym + sizeof(sym);
1085 int decode = (fmt[0] == 'R') ? 1 : 0;
1086 const struct printf_spec *specp;
1087
1088 if (check_pointer(&buf, end, res, spec))
1089 return buf;
1090
1091 *p++ = '[';
1092 if (res->flags & IORESOURCE_IO) {
1093 p = string_nocheck(p, pend, "io ", str_spec);
1094 specp = &io_spec;
1095 } else if (res->flags & IORESOURCE_MEM) {
1096 p = string_nocheck(p, pend, "mem ", str_spec);
1097 specp = &mem_spec;
1098 } else if (res->flags & IORESOURCE_IRQ) {
1099 p = string_nocheck(p, pend, "irq ", str_spec);
1100 specp = &default_dec_spec;
1101 } else if (res->flags & IORESOURCE_DMA) {
1102 p = string_nocheck(p, pend, "dma ", str_spec);
1103 specp = &default_dec_spec;
1104 } else if (res->flags & IORESOURCE_BUS) {
1105 p = string_nocheck(p, pend, "bus ", str_spec);
1106 specp = &bus_spec;
1107 } else {
1108 p = string_nocheck(p, pend, "??? ", str_spec);
1109 specp = &mem_spec;
1110 decode = 0;
1111 }
1112 if (decode && res->flags & IORESOURCE_UNSET) {
1113 p = string_nocheck(p, pend, "size ", str_spec);
1114 p = number(p, pend, resource_size(res), *specp);
1115 } else {
1116 p = number(p, pend, res->start, *specp);
1117 if (res->start != res->end) {
1118 *p++ = '-';
1119 p = number(p, pend, res->end, *specp);
1120 }
1121 }
1122 if (decode) {
1123 if (res->flags & IORESOURCE_MEM_64)
1124 p = string_nocheck(p, pend, " 64bit", str_spec);
1125 if (res->flags & IORESOURCE_PREFETCH)
1126 p = string_nocheck(p, pend, " pref", str_spec);
1127 if (res->flags & IORESOURCE_WINDOW)
1128 p = string_nocheck(p, pend, " window", str_spec);
1129 if (res->flags & IORESOURCE_DISABLED)
1130 p = string_nocheck(p, pend, " disabled", str_spec);
1131 } else {
1132 p = string_nocheck(p, pend, " flags ", str_spec);
1133 p = number(p, pend, res->flags, default_flag_spec);
1134 }
1135 *p++ = ']';
1136 *p = '\0';
1137
1138 return string_nocheck(buf, end, sym, spec);
1139 }
1140
1141 static noinline_for_stack
hex_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1142 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1143 const char *fmt)
1144 {
1145 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
1146 negative value, fallback to the default */
1147 char separator;
1148
1149 if (spec.field_width == 0)
1150 /* nothing to print */
1151 return buf;
1152
1153 if (check_pointer(&buf, end, addr, spec))
1154 return buf;
1155
1156 switch (fmt[1]) {
1157 case 'C':
1158 separator = ':';
1159 break;
1160 case 'D':
1161 separator = '-';
1162 break;
1163 case 'N':
1164 separator = 0;
1165 break;
1166 default:
1167 separator = ' ';
1168 break;
1169 }
1170
1171 if (spec.field_width > 0)
1172 len = min_t(int, spec.field_width, 64);
1173
1174 for (i = 0; i < len; ++i) {
1175 if (buf < end)
1176 *buf = hex_asc_hi(addr[i]);
1177 ++buf;
1178 if (buf < end)
1179 *buf = hex_asc_lo(addr[i]);
1180 ++buf;
1181
1182 if (separator && i != len - 1) {
1183 if (buf < end)
1184 *buf = separator;
1185 ++buf;
1186 }
1187 }
1188
1189 return buf;
1190 }
1191
1192 static noinline_for_stack
bitmap_string(char * buf,char * end,unsigned long * bitmap,struct printf_spec spec,const char * fmt)1193 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
1194 struct printf_spec spec, const char *fmt)
1195 {
1196 const int CHUNKSZ = 32;
1197 int nr_bits = max_t(int, spec.field_width, 0);
1198 int i, chunksz;
1199 bool first = true;
1200
1201 if (check_pointer(&buf, end, bitmap, spec))
1202 return buf;
1203
1204 /* reused to print numbers */
1205 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
1206
1207 chunksz = nr_bits & (CHUNKSZ - 1);
1208 if (chunksz == 0)
1209 chunksz = CHUNKSZ;
1210
1211 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
1212 for (; i >= 0; i -= CHUNKSZ) {
1213 u32 chunkmask, val;
1214 int word, bit;
1215
1216 chunkmask = ((1ULL << chunksz) - 1);
1217 word = i / BITS_PER_LONG;
1218 bit = i % BITS_PER_LONG;
1219 val = (bitmap[word] >> bit) & chunkmask;
1220
1221 if (!first) {
1222 if (buf < end)
1223 *buf = ',';
1224 buf++;
1225 }
1226 first = false;
1227
1228 spec.field_width = DIV_ROUND_UP(chunksz, 4);
1229 buf = number(buf, end, val, spec);
1230
1231 chunksz = CHUNKSZ;
1232 }
1233 return buf;
1234 }
1235
1236 static noinline_for_stack
bitmap_list_string(char * buf,char * end,unsigned long * bitmap,struct printf_spec spec,const char * fmt)1237 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
1238 struct printf_spec spec, const char *fmt)
1239 {
1240 int nr_bits = max_t(int, spec.field_width, 0);
1241 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1242 int cur, rbot, rtop;
1243 bool first = true;
1244
1245 if (check_pointer(&buf, end, bitmap, spec))
1246 return buf;
1247
1248 rbot = cur = find_first_bit(bitmap, nr_bits);
1249 while (cur < nr_bits) {
1250 rtop = cur;
1251 cur = find_next_bit(bitmap, nr_bits, cur + 1);
1252 if (cur < nr_bits && cur <= rtop + 1)
1253 continue;
1254
1255 if (!first) {
1256 if (buf < end)
1257 *buf = ',';
1258 buf++;
1259 }
1260 first = false;
1261
1262 buf = number(buf, end, rbot, default_dec_spec);
1263 if (rbot < rtop) {
1264 if (buf < end)
1265 *buf = '-';
1266 buf++;
1267
1268 buf = number(buf, end, rtop, default_dec_spec);
1269 }
1270
1271 rbot = cur;
1272 }
1273 return buf;
1274 }
1275
1276 static noinline_for_stack
mac_address_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1277 char *mac_address_string(char *buf, char *end, u8 *addr,
1278 struct printf_spec spec, const char *fmt)
1279 {
1280 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
1281 char *p = mac_addr;
1282 int i;
1283 char separator;
1284 bool reversed = false;
1285
1286 if (check_pointer(&buf, end, addr, spec))
1287 return buf;
1288
1289 switch (fmt[1]) {
1290 case 'F':
1291 separator = '-';
1292 break;
1293
1294 case 'R':
1295 reversed = true;
1296 /* fall through */
1297
1298 default:
1299 separator = ':';
1300 break;
1301 }
1302
1303 for (i = 0; i < 6; i++) {
1304 if (reversed)
1305 p = hex_byte_pack(p, addr[5 - i]);
1306 else
1307 p = hex_byte_pack(p, addr[i]);
1308
1309 if (fmt[0] == 'M' && i != 5)
1310 *p++ = separator;
1311 }
1312 *p = '\0';
1313
1314 return string_nocheck(buf, end, mac_addr, spec);
1315 }
1316
1317 static noinline_for_stack
ip4_string(char * p,const u8 * addr,const char * fmt)1318 char *ip4_string(char *p, const u8 *addr, const char *fmt)
1319 {
1320 int i;
1321 bool leading_zeros = (fmt[0] == 'i');
1322 int index;
1323 int step;
1324
1325 switch (fmt[2]) {
1326 case 'h':
1327 #ifdef __BIG_ENDIAN
1328 index = 0;
1329 step = 1;
1330 #else
1331 index = 3;
1332 step = -1;
1333 #endif
1334 break;
1335 case 'l':
1336 index = 3;
1337 step = -1;
1338 break;
1339 case 'n':
1340 case 'b':
1341 default:
1342 index = 0;
1343 step = 1;
1344 break;
1345 }
1346 for (i = 0; i < 4; i++) {
1347 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1348 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1349 if (leading_zeros) {
1350 if (digits < 3)
1351 *p++ = '0';
1352 if (digits < 2)
1353 *p++ = '0';
1354 }
1355 /* reverse the digits in the quad */
1356 while (digits--)
1357 *p++ = temp[digits];
1358 if (i < 3)
1359 *p++ = '.';
1360 index += step;
1361 }
1362 *p = '\0';
1363
1364 return p;
1365 }
1366
1367 static noinline_for_stack
ip6_compressed_string(char * p,const char * addr)1368 char *ip6_compressed_string(char *p, const char *addr)
1369 {
1370 int i, j, range;
1371 unsigned char zerolength[8];
1372 int longest = 1;
1373 int colonpos = -1;
1374 u16 word;
1375 u8 hi, lo;
1376 bool needcolon = false;
1377 bool useIPv4;
1378 struct in6_addr in6;
1379
1380 memcpy(&in6, addr, sizeof(struct in6_addr));
1381
1382 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1383
1384 memset(zerolength, 0, sizeof(zerolength));
1385
1386 if (useIPv4)
1387 range = 6;
1388 else
1389 range = 8;
1390
1391 /* find position of longest 0 run */
1392 for (i = 0; i < range; i++) {
1393 for (j = i; j < range; j++) {
1394 if (in6.s6_addr16[j] != 0)
1395 break;
1396 zerolength[i]++;
1397 }
1398 }
1399 for (i = 0; i < range; i++) {
1400 if (zerolength[i] > longest) {
1401 longest = zerolength[i];
1402 colonpos = i;
1403 }
1404 }
1405 if (longest == 1) /* don't compress a single 0 */
1406 colonpos = -1;
1407
1408 /* emit address */
1409 for (i = 0; i < range; i++) {
1410 if (i == colonpos) {
1411 if (needcolon || i == 0)
1412 *p++ = ':';
1413 *p++ = ':';
1414 needcolon = false;
1415 i += longest - 1;
1416 continue;
1417 }
1418 if (needcolon) {
1419 *p++ = ':';
1420 needcolon = false;
1421 }
1422 /* hex u16 without leading 0s */
1423 word = ntohs(in6.s6_addr16[i]);
1424 hi = word >> 8;
1425 lo = word & 0xff;
1426 if (hi) {
1427 if (hi > 0x0f)
1428 p = hex_byte_pack(p, hi);
1429 else
1430 *p++ = hex_asc_lo(hi);
1431 p = hex_byte_pack(p, lo);
1432 }
1433 else if (lo > 0x0f)
1434 p = hex_byte_pack(p, lo);
1435 else
1436 *p++ = hex_asc_lo(lo);
1437 needcolon = true;
1438 }
1439
1440 if (useIPv4) {
1441 if (needcolon)
1442 *p++ = ':';
1443 p = ip4_string(p, &in6.s6_addr[12], "I4");
1444 }
1445 *p = '\0';
1446
1447 return p;
1448 }
1449
1450 static noinline_for_stack
ip6_string(char * p,const char * addr,const char * fmt)1451 char *ip6_string(char *p, const char *addr, const char *fmt)
1452 {
1453 int i;
1454
1455 for (i = 0; i < 8; i++) {
1456 p = hex_byte_pack(p, *addr++);
1457 p = hex_byte_pack(p, *addr++);
1458 if (fmt[0] == 'I' && i != 7)
1459 *p++ = ':';
1460 }
1461 *p = '\0';
1462
1463 return p;
1464 }
1465
1466 static noinline_for_stack
ip6_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1467 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1468 struct printf_spec spec, const char *fmt)
1469 {
1470 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1471
1472 if (fmt[0] == 'I' && fmt[2] == 'c')
1473 ip6_compressed_string(ip6_addr, addr);
1474 else
1475 ip6_string(ip6_addr, addr, fmt);
1476
1477 return string_nocheck(buf, end, ip6_addr, spec);
1478 }
1479
1480 static noinline_for_stack
ip4_addr_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1481 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1482 struct printf_spec spec, const char *fmt)
1483 {
1484 char ip4_addr[sizeof("255.255.255.255")];
1485
1486 ip4_string(ip4_addr, addr, fmt);
1487
1488 return string_nocheck(buf, end, ip4_addr, spec);
1489 }
1490
1491 static noinline_for_stack
ip6_addr_string_sa(char * buf,char * end,const struct sockaddr_in6 * sa,struct printf_spec spec,const char * fmt)1492 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1493 struct printf_spec spec, const char *fmt)
1494 {
1495 bool have_p = false, have_s = false, have_f = false, have_c = false;
1496 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1497 sizeof(":12345") + sizeof("/123456789") +
1498 sizeof("%1234567890")];
1499 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1500 const u8 *addr = (const u8 *) &sa->sin6_addr;
1501 char fmt6[2] = { fmt[0], '6' };
1502 u8 off = 0;
1503
1504 fmt++;
1505 while (isalpha(*++fmt)) {
1506 switch (*fmt) {
1507 case 'p':
1508 have_p = true;
1509 break;
1510 case 'f':
1511 have_f = true;
1512 break;
1513 case 's':
1514 have_s = true;
1515 break;
1516 case 'c':
1517 have_c = true;
1518 break;
1519 }
1520 }
1521
1522 if (have_p || have_s || have_f) {
1523 *p = '[';
1524 off = 1;
1525 }
1526
1527 if (fmt6[0] == 'I' && have_c)
1528 p = ip6_compressed_string(ip6_addr + off, addr);
1529 else
1530 p = ip6_string(ip6_addr + off, addr, fmt6);
1531
1532 if (have_p || have_s || have_f)
1533 *p++ = ']';
1534
1535 if (have_p) {
1536 *p++ = ':';
1537 p = number(p, pend, ntohs(sa->sin6_port), spec);
1538 }
1539 if (have_f) {
1540 *p++ = '/';
1541 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1542 IPV6_FLOWINFO_MASK), spec);
1543 }
1544 if (have_s) {
1545 *p++ = '%';
1546 p = number(p, pend, sa->sin6_scope_id, spec);
1547 }
1548 *p = '\0';
1549
1550 return string_nocheck(buf, end, ip6_addr, spec);
1551 }
1552
1553 static noinline_for_stack
ip4_addr_string_sa(char * buf,char * end,const struct sockaddr_in * sa,struct printf_spec spec,const char * fmt)1554 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1555 struct printf_spec spec, const char *fmt)
1556 {
1557 bool have_p = false;
1558 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1559 char *pend = ip4_addr + sizeof(ip4_addr);
1560 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1561 char fmt4[3] = { fmt[0], '4', 0 };
1562
1563 fmt++;
1564 while (isalpha(*++fmt)) {
1565 switch (*fmt) {
1566 case 'p':
1567 have_p = true;
1568 break;
1569 case 'h':
1570 case 'l':
1571 case 'n':
1572 case 'b':
1573 fmt4[2] = *fmt;
1574 break;
1575 }
1576 }
1577
1578 p = ip4_string(ip4_addr, addr, fmt4);
1579 if (have_p) {
1580 *p++ = ':';
1581 p = number(p, pend, ntohs(sa->sin_port), spec);
1582 }
1583 *p = '\0';
1584
1585 return string_nocheck(buf, end, ip4_addr, spec);
1586 }
1587
1588 static noinline_for_stack
ip_addr_string(char * buf,char * end,const void * ptr,struct printf_spec spec,const char * fmt)1589 char *ip_addr_string(char *buf, char *end, const void *ptr,
1590 struct printf_spec spec, const char *fmt)
1591 {
1592 char *err_fmt_msg;
1593
1594 if (check_pointer(&buf, end, ptr, spec))
1595 return buf;
1596
1597 switch (fmt[1]) {
1598 case '6':
1599 return ip6_addr_string(buf, end, ptr, spec, fmt);
1600 case '4':
1601 return ip4_addr_string(buf, end, ptr, spec, fmt);
1602 case 'S': {
1603 const union {
1604 struct sockaddr raw;
1605 struct sockaddr_in v4;
1606 struct sockaddr_in6 v6;
1607 } *sa = ptr;
1608
1609 switch (sa->raw.sa_family) {
1610 case AF_INET:
1611 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1612 case AF_INET6:
1613 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1614 default:
1615 return error_string(buf, end, "(einval)", spec);
1616 }}
1617 }
1618
1619 err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)";
1620 return error_string(buf, end, err_fmt_msg, spec);
1621 }
1622
1623 static noinline_for_stack
escaped_string(char * buf,char * end,u8 * addr,struct printf_spec spec,const char * fmt)1624 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1625 const char *fmt)
1626 {
1627 bool found = true;
1628 int count = 1;
1629 unsigned int flags = 0;
1630 int len;
1631
1632 if (spec.field_width == 0)
1633 return buf; /* nothing to print */
1634
1635 if (check_pointer(&buf, end, addr, spec))
1636 return buf;
1637
1638 do {
1639 switch (fmt[count++]) {
1640 case 'a':
1641 flags |= ESCAPE_ANY;
1642 break;
1643 case 'c':
1644 flags |= ESCAPE_SPECIAL;
1645 break;
1646 case 'h':
1647 flags |= ESCAPE_HEX;
1648 break;
1649 case 'n':
1650 flags |= ESCAPE_NULL;
1651 break;
1652 case 'o':
1653 flags |= ESCAPE_OCTAL;
1654 break;
1655 case 'p':
1656 flags |= ESCAPE_NP;
1657 break;
1658 case 's':
1659 flags |= ESCAPE_SPACE;
1660 break;
1661 default:
1662 found = false;
1663 break;
1664 }
1665 } while (found);
1666
1667 if (!flags)
1668 flags = ESCAPE_ANY_NP;
1669
1670 len = spec.field_width < 0 ? 1 : spec.field_width;
1671
1672 /*
1673 * string_escape_mem() writes as many characters as it can to
1674 * the given buffer, and returns the total size of the output
1675 * had the buffer been big enough.
1676 */
1677 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1678
1679 return buf;
1680 }
1681
va_format(char * buf,char * end,struct va_format * va_fmt,struct printf_spec spec,const char * fmt)1682 static char *va_format(char *buf, char *end, struct va_format *va_fmt,
1683 struct printf_spec spec, const char *fmt)
1684 {
1685 va_list va;
1686
1687 if (check_pointer(&buf, end, va_fmt, spec))
1688 return buf;
1689
1690 va_copy(va, *va_fmt->va);
1691 buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
1692 va_end(va);
1693
1694 return buf;
1695 }
1696
1697 static noinline_for_stack
uuid_string(char * buf,char * end,const u8 * addr,struct printf_spec spec,const char * fmt)1698 char *uuid_string(char *buf, char *end, const u8 *addr,
1699 struct printf_spec spec, const char *fmt)
1700 {
1701 char uuid[UUID_STRING_LEN + 1];
1702 char *p = uuid;
1703 int i;
1704 const u8 *index = uuid_index;
1705 bool uc = false;
1706
1707 if (check_pointer(&buf, end, addr, spec))
1708 return buf;
1709
1710 switch (*(++fmt)) {
1711 case 'L':
1712 uc = true;
1713 /* fall through */
1714 case 'l':
1715 index = guid_index;
1716 break;
1717 case 'B':
1718 uc = true;
1719 break;
1720 }
1721
1722 for (i = 0; i < 16; i++) {
1723 if (uc)
1724 p = hex_byte_pack_upper(p, addr[index[i]]);
1725 else
1726 p = hex_byte_pack(p, addr[index[i]]);
1727 switch (i) {
1728 case 3:
1729 case 5:
1730 case 7:
1731 case 9:
1732 *p++ = '-';
1733 break;
1734 }
1735 }
1736
1737 *p = 0;
1738
1739 return string_nocheck(buf, end, uuid, spec);
1740 }
1741
1742 static noinline_for_stack
netdev_bits(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1743 char *netdev_bits(char *buf, char *end, const void *addr,
1744 struct printf_spec spec, const char *fmt)
1745 {
1746 unsigned long long num;
1747 int size;
1748
1749 if (check_pointer(&buf, end, addr, spec))
1750 return buf;
1751
1752 switch (fmt[1]) {
1753 case 'F':
1754 num = *(const netdev_features_t *)addr;
1755 size = sizeof(netdev_features_t);
1756 break;
1757 default:
1758 return error_string(buf, end, "(%pN?)", spec);
1759 }
1760
1761 return special_hex_number(buf, end, num, size);
1762 }
1763
1764 static noinline_for_stack
address_val(char * buf,char * end,const void * addr,struct printf_spec spec,const char * fmt)1765 char *address_val(char *buf, char *end, const void *addr,
1766 struct printf_spec spec, const char *fmt)
1767 {
1768 unsigned long long num;
1769 int size;
1770
1771 if (check_pointer(&buf, end, addr, spec))
1772 return buf;
1773
1774 switch (fmt[1]) {
1775 case 'd':
1776 num = *(const dma_addr_t *)addr;
1777 size = sizeof(dma_addr_t);
1778 break;
1779 case 'p':
1780 default:
1781 num = *(const phys_addr_t *)addr;
1782 size = sizeof(phys_addr_t);
1783 break;
1784 }
1785
1786 return special_hex_number(buf, end, num, size);
1787 }
1788
1789 static noinline_for_stack
date_str(char * buf,char * end,const struct rtc_time * tm,bool r)1790 char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1791 {
1792 int year = tm->tm_year + (r ? 0 : 1900);
1793 int mon = tm->tm_mon + (r ? 0 : 1);
1794
1795 buf = number(buf, end, year, default_dec04_spec);
1796 if (buf < end)
1797 *buf = '-';
1798 buf++;
1799
1800 buf = number(buf, end, mon, default_dec02_spec);
1801 if (buf < end)
1802 *buf = '-';
1803 buf++;
1804
1805 return number(buf, end, tm->tm_mday, default_dec02_spec);
1806 }
1807
1808 static noinline_for_stack
time_str(char * buf,char * end,const struct rtc_time * tm,bool r)1809 char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r)
1810 {
1811 buf = number(buf, end, tm->tm_hour, default_dec02_spec);
1812 if (buf < end)
1813 *buf = ':';
1814 buf++;
1815
1816 buf = number(buf, end, tm->tm_min, default_dec02_spec);
1817 if (buf < end)
1818 *buf = ':';
1819 buf++;
1820
1821 return number(buf, end, tm->tm_sec, default_dec02_spec);
1822 }
1823
1824 static noinline_for_stack
rtc_str(char * buf,char * end,const struct rtc_time * tm,struct printf_spec spec,const char * fmt)1825 char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
1826 struct printf_spec spec, const char *fmt)
1827 {
1828 bool have_t = true, have_d = true;
1829 bool raw = false;
1830 int count = 2;
1831
1832 if (check_pointer(&buf, end, tm, spec))
1833 return buf;
1834
1835 switch (fmt[count]) {
1836 case 'd':
1837 have_t = false;
1838 count++;
1839 break;
1840 case 't':
1841 have_d = false;
1842 count++;
1843 break;
1844 }
1845
1846 raw = fmt[count] == 'r';
1847
1848 if (have_d)
1849 buf = date_str(buf, end, tm, raw);
1850 if (have_d && have_t) {
1851 /* Respect ISO 8601 */
1852 if (buf < end)
1853 *buf = 'T';
1854 buf++;
1855 }
1856 if (have_t)
1857 buf = time_str(buf, end, tm, raw);
1858
1859 return buf;
1860 }
1861
1862 static noinline_for_stack
time64_str(char * buf,char * end,const time64_t time,struct printf_spec spec,const char * fmt)1863 char *time64_str(char *buf, char *end, const time64_t time,
1864 struct printf_spec spec, const char *fmt)
1865 {
1866 struct rtc_time rtc_time;
1867 struct tm tm;
1868
1869 time64_to_tm(time, 0, &tm);
1870
1871 rtc_time.tm_sec = tm.tm_sec;
1872 rtc_time.tm_min = tm.tm_min;
1873 rtc_time.tm_hour = tm.tm_hour;
1874 rtc_time.tm_mday = tm.tm_mday;
1875 rtc_time.tm_mon = tm.tm_mon;
1876 rtc_time.tm_year = tm.tm_year;
1877 rtc_time.tm_wday = tm.tm_wday;
1878 rtc_time.tm_yday = tm.tm_yday;
1879
1880 rtc_time.tm_isdst = 0;
1881
1882 return rtc_str(buf, end, &rtc_time, spec, fmt);
1883 }
1884
1885 static noinline_for_stack
time_and_date(char * buf,char * end,void * ptr,struct printf_spec spec,const char * fmt)1886 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
1887 const char *fmt)
1888 {
1889 switch (fmt[1]) {
1890 case 'R':
1891 return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
1892 case 'T':
1893 return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
1894 default:
1895 return error_string(buf, end, "(%pt?)", spec);
1896 }
1897 }
1898
1899 static noinline_for_stack
clock(char * buf,char * end,struct clk * clk,struct printf_spec spec,const char * fmt)1900 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1901 const char *fmt)
1902 {
1903 if (!IS_ENABLED(CONFIG_HAVE_CLK))
1904 return error_string(buf, end, "(%pC?)", spec);
1905
1906 if (check_pointer(&buf, end, clk, spec))
1907 return buf;
1908
1909 switch (fmt[1]) {
1910 case 'n':
1911 default:
1912 #ifdef CONFIG_COMMON_CLK
1913 return string(buf, end, __clk_get_name(clk), spec);
1914 #else
1915 return ptr_to_id(buf, end, clk, spec);
1916 #endif
1917 }
1918 }
1919
1920 static
format_flags(char * buf,char * end,unsigned long flags,const struct trace_print_flags * names)1921 char *format_flags(char *buf, char *end, unsigned long flags,
1922 const struct trace_print_flags *names)
1923 {
1924 unsigned long mask;
1925
1926 for ( ; flags && names->name; names++) {
1927 mask = names->mask;
1928 if ((flags & mask) != mask)
1929 continue;
1930
1931 buf = string(buf, end, names->name, default_str_spec);
1932
1933 flags &= ~mask;
1934 if (flags) {
1935 if (buf < end)
1936 *buf = '|';
1937 buf++;
1938 }
1939 }
1940
1941 if (flags)
1942 buf = number(buf, end, flags, default_flag_spec);
1943
1944 return buf;
1945 }
1946
1947 static noinline_for_stack
flags_string(char * buf,char * end,void * flags_ptr,struct printf_spec spec,const char * fmt)1948 char *flags_string(char *buf, char *end, void *flags_ptr,
1949 struct printf_spec spec, const char *fmt)
1950 {
1951 unsigned long flags;
1952 const struct trace_print_flags *names;
1953
1954 if (check_pointer(&buf, end, flags_ptr, spec))
1955 return buf;
1956
1957 switch (fmt[1]) {
1958 case 'p':
1959 flags = *(unsigned long *)flags_ptr;
1960 /* Remove zone id */
1961 flags &= (1UL << NR_PAGEFLAGS) - 1;
1962 names = pageflag_names;
1963 break;
1964 case 'v':
1965 flags = *(unsigned long *)flags_ptr;
1966 names = vmaflag_names;
1967 break;
1968 case 'g':
1969 flags = (__force unsigned long)(*(gfp_t *)flags_ptr);
1970 names = gfpflag_names;
1971 break;
1972 default:
1973 return error_string(buf, end, "(%pG?)", spec);
1974 }
1975
1976 return format_flags(buf, end, flags, names);
1977 }
1978
1979 static noinline_for_stack
fwnode_full_name_string(struct fwnode_handle * fwnode,char * buf,char * end)1980 char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf,
1981 char *end)
1982 {
1983 int depth;
1984
1985 /* Loop starting from the root node to the current node. */
1986 for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) {
1987 /*
1988 * Only get a reference for other nodes (i.e. parent nodes).
1989 * fwnode refcount may be 0 here.
1990 */
1991 struct fwnode_handle *__fwnode = depth ?
1992 fwnode_get_nth_parent(fwnode, depth) : fwnode;
1993
1994 buf = string(buf, end, fwnode_get_name_prefix(__fwnode),
1995 default_str_spec);
1996 buf = string(buf, end, fwnode_get_name(__fwnode),
1997 default_str_spec);
1998
1999 if (depth)
2000 fwnode_handle_put(__fwnode);
2001 }
2002
2003 return buf;
2004 }
2005
2006 static noinline_for_stack
device_node_string(char * buf,char * end,struct device_node * dn,struct printf_spec spec,const char * fmt)2007 char *device_node_string(char *buf, char *end, struct device_node *dn,
2008 struct printf_spec spec, const char *fmt)
2009 {
2010 char tbuf[sizeof("xxxx") + 1];
2011 const char *p;
2012 int ret;
2013 char *buf_start = buf;
2014 struct property *prop;
2015 bool has_mult, pass;
2016
2017 struct printf_spec str_spec = spec;
2018 str_spec.field_width = -1;
2019
2020 if (fmt[0] != 'F')
2021 return error_string(buf, end, "(%pO?)", spec);
2022
2023 if (!IS_ENABLED(CONFIG_OF))
2024 return error_string(buf, end, "(%pOF?)", spec);
2025
2026 if (check_pointer(&buf, end, dn, spec))
2027 return buf;
2028
2029 /* simple case without anything any more format specifiers */
2030 fmt++;
2031 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
2032 fmt = "f";
2033
2034 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
2035 int precision;
2036 if (pass) {
2037 if (buf < end)
2038 *buf = ':';
2039 buf++;
2040 }
2041
2042 switch (*fmt) {
2043 case 'f': /* full_name */
2044 buf = fwnode_full_name_string(of_fwnode_handle(dn), buf,
2045 end);
2046 break;
2047 case 'n': /* name */
2048 p = fwnode_get_name(of_fwnode_handle(dn));
2049 precision = str_spec.precision;
2050 str_spec.precision = strchrnul(p, '@') - p;
2051 buf = string(buf, end, p, str_spec);
2052 str_spec.precision = precision;
2053 break;
2054 case 'p': /* phandle */
2055 buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec);
2056 break;
2057 case 'P': /* path-spec */
2058 p = fwnode_get_name(of_fwnode_handle(dn));
2059 if (!p[1])
2060 p = "/";
2061 buf = string(buf, end, p, str_spec);
2062 break;
2063 case 'F': /* flags */
2064 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
2065 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
2066 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
2067 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
2068 tbuf[4] = 0;
2069 buf = string_nocheck(buf, end, tbuf, str_spec);
2070 break;
2071 case 'c': /* major compatible string */
2072 ret = of_property_read_string(dn, "compatible", &p);
2073 if (!ret)
2074 buf = string(buf, end, p, str_spec);
2075 break;
2076 case 'C': /* full compatible string */
2077 has_mult = false;
2078 of_property_for_each_string(dn, "compatible", prop, p) {
2079 if (has_mult)
2080 buf = string_nocheck(buf, end, ",", str_spec);
2081 buf = string_nocheck(buf, end, "\"", str_spec);
2082 buf = string(buf, end, p, str_spec);
2083 buf = string_nocheck(buf, end, "\"", str_spec);
2084
2085 has_mult = true;
2086 }
2087 break;
2088 default:
2089 break;
2090 }
2091 }
2092
2093 return widen_string(buf, buf - buf_start, end, spec);
2094 }
2095
2096 static noinline_for_stack
fwnode_string(char * buf,char * end,struct fwnode_handle * fwnode,struct printf_spec spec,const char * fmt)2097 char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
2098 struct printf_spec spec, const char *fmt)
2099 {
2100 struct printf_spec str_spec = spec;
2101 char *buf_start = buf;
2102
2103 str_spec.field_width = -1;
2104
2105 if (*fmt != 'w')
2106 return error_string(buf, end, "(%pf?)", spec);
2107
2108 if (check_pointer(&buf, end, fwnode, spec))
2109 return buf;
2110
2111 fmt++;
2112
2113 switch (*fmt) {
2114 case 'P': /* name */
2115 buf = string(buf, end, fwnode_get_name(fwnode), str_spec);
2116 break;
2117 case 'f': /* full_name */
2118 default:
2119 buf = fwnode_full_name_string(fwnode, buf, end);
2120 break;
2121 }
2122
2123 return widen_string(buf, buf - buf_start, end, spec);
2124 }
2125
2126 /*
2127 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2128 * by an extra set of alphanumeric characters that are extended format
2129 * specifiers.
2130 *
2131 * Please update scripts/checkpatch.pl when adding/removing conversion
2132 * characters. (Search for "check for vsprintf extension").
2133 *
2134 * Right now we handle:
2135 *
2136 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2137 * - 's' For symbolic direct pointers (or function descriptors) without offset
2138 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2139 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2140 * %ps and %pS. Be careful when re-using these specifiers.
2141 * - 'B' For backtraced symbolic direct pointers with offset
2142 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2143 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2144 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2145 * width which must be explicitly specified either as part of the
2146 * format string '%32b[l]' or through '%*b[l]', [l] selects
2147 * range-list format instead of hex format
2148 * - 'M' For a 6-byte MAC address, it prints the address in the
2149 * usual colon-separated hex notation
2150 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2151 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2152 * with a dash-separated hex notation
2153 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2154 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2155 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2156 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2157 * [S][pfs]
2158 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2159 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2160 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2161 * IPv6 omits the colons (01020304...0f)
2162 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2163 * [S][pfs]
2164 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2165 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2166 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2167 * - 'I[6S]c' for IPv6 addresses printed as specified by
2168 * https://tools.ietf.org/html/rfc5952
2169 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2170 * of the following flags (see string_escape_mem() for the
2171 * details):
2172 * a - ESCAPE_ANY
2173 * c - ESCAPE_SPECIAL
2174 * h - ESCAPE_HEX
2175 * n - ESCAPE_NULL
2176 * o - ESCAPE_OCTAL
2177 * p - ESCAPE_NP
2178 * s - ESCAPE_SPACE
2179 * By default ESCAPE_ANY_NP is used.
2180 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2181 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2182 * Options for %pU are:
2183 * b big endian lower case hex (default)
2184 * B big endian UPPER case hex
2185 * l little endian lower case hex
2186 * L little endian UPPER case hex
2187 * big endian output byte order is:
2188 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2189 * little endian output byte order is:
2190 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2191 * - 'V' For a struct va_format which contains a format string * and va_list *,
2192 * call vsnprintf(->format, *->va_list).
2193 * Implements a "recursive vsnprintf".
2194 * Do not use this feature without some mechanism to verify the
2195 * correctness of the format string and va_list arguments.
2196 * - 'K' For a kernel pointer that should be hidden from unprivileged users
2197 * - 'NF' For a netdev_features_t
2198 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2199 * a certain separator (' ' by default):
2200 * C colon
2201 * D dash
2202 * N no separator
2203 * The maximum supported length is 64 bytes of the input. Consider
2204 * to use print_hex_dump() for the larger input.
2205 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2206 * (default assumed to be phys_addr_t, passed by reference)
2207 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2208 * - 'D[234]' Same as 'd' but for a struct file
2209 * - 'g' For block_device name (gendisk + partition number)
2210 * - 't[RT][dt][r]' For time and date as represented by:
2211 * R struct rtc_time
2212 * T time64_t
2213 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2214 * (legacy clock framework) of the clock
2215 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2216 * (legacy clock framework) of the clock
2217 * - 'G' For flags to be printed as a collection of symbolic strings that would
2218 * construct the specific value. Supported flags given by option:
2219 * p page flags (see struct page) given as pointer to unsigned long
2220 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2221 * v vma flags (VM_*) given as pointer to unsigned long
2222 * - 'OF[fnpPcCF]' For a device tree object
2223 * Without any optional arguments prints the full_name
2224 * f device node full_name
2225 * n device node name
2226 * p device node phandle
2227 * P device node path spec (name + @unit)
2228 * F device node flags
2229 * c major compatible string
2230 * C full compatible string
2231 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2232 * Without an option prints the full name of the node
2233 * f full name
2234 * P node name, including a possible unit address
2235 * - 'x' For printing the address. Equivalent to "%lx".
2236 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2237 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2238 * or user (u) memory to probe, and:
2239 * s a string, equivalent to "%s" on direct vsnprintf() use
2240 *
2241 * ** When making changes please also update:
2242 * Documentation/core-api/printk-formats.rst
2243 *
2244 * Note: The default behaviour (unadorned %p) is to hash the address,
2245 * rendering it useful as a unique identifier.
2246 */
2247 static noinline_for_stack
pointer(const char * fmt,char * buf,char * end,void * ptr,struct printf_spec spec)2248 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
2249 struct printf_spec spec)
2250 {
2251 switch (*fmt) {
2252 case 'S':
2253 case 's':
2254 ptr = dereference_symbol_descriptor(ptr);
2255 /* fall through */
2256 case 'B':
2257 return symbol_string(buf, end, ptr, spec, fmt);
2258 case 'R':
2259 case 'r':
2260 return resource_string(buf, end, ptr, spec, fmt);
2261 case 'h':
2262 return hex_string(buf, end, ptr, spec, fmt);
2263 case 'b':
2264 switch (fmt[1]) {
2265 case 'l':
2266 return bitmap_list_string(buf, end, ptr, spec, fmt);
2267 default:
2268 return bitmap_string(buf, end, ptr, spec, fmt);
2269 }
2270 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2271 case 'm': /* Contiguous: 000102030405 */
2272 /* [mM]F (FDDI) */
2273 /* [mM]R (Reverse order; Bluetooth) */
2274 return mac_address_string(buf, end, ptr, spec, fmt);
2275 case 'I': /* Formatted IP supported
2276 * 4: 1.2.3.4
2277 * 6: 0001:0203:...:0708
2278 * 6c: 1::708 or 1::1.2.3.4
2279 */
2280 case 'i': /* Contiguous:
2281 * 4: 001.002.003.004
2282 * 6: 000102...0f
2283 */
2284 return ip_addr_string(buf, end, ptr, spec, fmt);
2285 case 'E':
2286 return escaped_string(buf, end, ptr, spec, fmt);
2287 case 'U':
2288 return uuid_string(buf, end, ptr, spec, fmt);
2289 case 'V':
2290 return va_format(buf, end, ptr, spec, fmt);
2291 case 'K':
2292 return restricted_pointer(buf, end, ptr, spec);
2293 case 'N':
2294 return netdev_bits(buf, end, ptr, spec, fmt);
2295 case 'a':
2296 return address_val(buf, end, ptr, spec, fmt);
2297 case 'd':
2298 return dentry_name(buf, end, ptr, spec, fmt);
2299 case 't':
2300 return time_and_date(buf, end, ptr, spec, fmt);
2301 case 'C':
2302 return clock(buf, end, ptr, spec, fmt);
2303 case 'D':
2304 return file_dentry_name(buf, end, ptr, spec, fmt);
2305 #ifdef CONFIG_BLOCK
2306 case 'g':
2307 return bdev_name(buf, end, ptr, spec, fmt);
2308 #endif
2309
2310 case 'G':
2311 return flags_string(buf, end, ptr, spec, fmt);
2312 case 'O':
2313 return device_node_string(buf, end, ptr, spec, fmt + 1);
2314 case 'f':
2315 return fwnode_string(buf, end, ptr, spec, fmt + 1);
2316 case 'x':
2317 return pointer_string(buf, end, ptr, spec);
2318 case 'e':
2319 /* %pe with a non-ERR_PTR gets treated as plain %p */
2320 if (!IS_ERR(ptr))
2321 break;
2322 return err_ptr(buf, end, ptr, spec);
2323 case 'u':
2324 case 'k':
2325 switch (fmt[1]) {
2326 case 's':
2327 return string(buf, end, ptr, spec);
2328 default:
2329 return error_string(buf, end, "(einval)", spec);
2330 }
2331 }
2332
2333 /* default is to _not_ leak addresses, hash before printing */
2334 return ptr_to_id(buf, end, ptr, spec);
2335 }
2336
2337 /*
2338 * Helper function to decode printf style format.
2339 * Each call decode a token from the format and return the
2340 * number of characters read (or likely the delta where it wants
2341 * to go on the next call).
2342 * The decoded token is returned through the parameters
2343 *
2344 * 'h', 'l', or 'L' for integer fields
2345 * 'z' support added 23/7/1999 S.H.
2346 * 'z' changed to 'Z' --davidm 1/25/99
2347 * 'Z' changed to 'z' --adobriyan 2017-01-25
2348 * 't' added for ptrdiff_t
2349 *
2350 * @fmt: the format string
2351 * @type of the token returned
2352 * @flags: various flags such as +, -, # tokens..
2353 * @field_width: overwritten width
2354 * @base: base of the number (octal, hex, ...)
2355 * @precision: precision of a number
2356 * @qualifier: qualifier of a number (long, size_t, ...)
2357 */
2358 static noinline_for_stack
format_decode(const char * fmt,struct printf_spec * spec)2359 int format_decode(const char *fmt, struct printf_spec *spec)
2360 {
2361 const char *start = fmt;
2362 char qualifier;
2363
2364 /* we finished early by reading the field width */
2365 if (spec->type == FORMAT_TYPE_WIDTH) {
2366 if (spec->field_width < 0) {
2367 spec->field_width = -spec->field_width;
2368 spec->flags |= LEFT;
2369 }
2370 spec->type = FORMAT_TYPE_NONE;
2371 goto precision;
2372 }
2373
2374 /* we finished early by reading the precision */
2375 if (spec->type == FORMAT_TYPE_PRECISION) {
2376 if (spec->precision < 0)
2377 spec->precision = 0;
2378
2379 spec->type = FORMAT_TYPE_NONE;
2380 goto qualifier;
2381 }
2382
2383 /* By default */
2384 spec->type = FORMAT_TYPE_NONE;
2385
2386 for (; *fmt ; ++fmt) {
2387 if (*fmt == '%')
2388 break;
2389 }
2390
2391 /* Return the current non-format string */
2392 if (fmt != start || !*fmt)
2393 return fmt - start;
2394
2395 /* Process flags */
2396 spec->flags = 0;
2397
2398 while (1) { /* this also skips first '%' */
2399 bool found = true;
2400
2401 ++fmt;
2402
2403 switch (*fmt) {
2404 case '-': spec->flags |= LEFT; break;
2405 case '+': spec->flags |= PLUS; break;
2406 case ' ': spec->flags |= SPACE; break;
2407 case '#': spec->flags |= SPECIAL; break;
2408 case '0': spec->flags |= ZEROPAD; break;
2409 default: found = false;
2410 }
2411
2412 if (!found)
2413 break;
2414 }
2415
2416 /* get field width */
2417 spec->field_width = -1;
2418
2419 if (isdigit(*fmt))
2420 spec->field_width = skip_atoi(&fmt);
2421 else if (*fmt == '*') {
2422 /* it's the next argument */
2423 spec->type = FORMAT_TYPE_WIDTH;
2424 return ++fmt - start;
2425 }
2426
2427 precision:
2428 /* get the precision */
2429 spec->precision = -1;
2430 if (*fmt == '.') {
2431 ++fmt;
2432 if (isdigit(*fmt)) {
2433 spec->precision = skip_atoi(&fmt);
2434 if (spec->precision < 0)
2435 spec->precision = 0;
2436 } else if (*fmt == '*') {
2437 /* it's the next argument */
2438 spec->type = FORMAT_TYPE_PRECISION;
2439 return ++fmt - start;
2440 }
2441 }
2442
2443 qualifier:
2444 /* get the conversion qualifier */
2445 qualifier = 0;
2446 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2447 *fmt == 'z' || *fmt == 't') {
2448 qualifier = *fmt++;
2449 if (unlikely(qualifier == *fmt)) {
2450 if (qualifier == 'l') {
2451 qualifier = 'L';
2452 ++fmt;
2453 } else if (qualifier == 'h') {
2454 qualifier = 'H';
2455 ++fmt;
2456 }
2457 }
2458 }
2459
2460 /* default base */
2461 spec->base = 10;
2462 switch (*fmt) {
2463 case 'c':
2464 spec->type = FORMAT_TYPE_CHAR;
2465 return ++fmt - start;
2466
2467 case 's':
2468 spec->type = FORMAT_TYPE_STR;
2469 return ++fmt - start;
2470
2471 case 'p':
2472 spec->type = FORMAT_TYPE_PTR;
2473 return ++fmt - start;
2474
2475 case '%':
2476 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2477 return ++fmt - start;
2478
2479 /* integer number formats - set up the flags and "break" */
2480 case 'o':
2481 spec->base = 8;
2482 break;
2483
2484 case 'x':
2485 spec->flags |= SMALL;
2486 /* fall through */
2487
2488 case 'X':
2489 spec->base = 16;
2490 break;
2491
2492 case 'd':
2493 case 'i':
2494 spec->flags |= SIGN;
2495 case 'u':
2496 break;
2497
2498 case 'n':
2499 /*
2500 * Since %n poses a greater security risk than
2501 * utility, treat it as any other invalid or
2502 * unsupported format specifier.
2503 */
2504 /* fall through */
2505
2506 default:
2507 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2508 spec->type = FORMAT_TYPE_INVALID;
2509 return fmt - start;
2510 }
2511
2512 if (qualifier == 'L')
2513 spec->type = FORMAT_TYPE_LONG_LONG;
2514 else if (qualifier == 'l') {
2515 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2516 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2517 } else if (qualifier == 'z') {
2518 spec->type = FORMAT_TYPE_SIZE_T;
2519 } else if (qualifier == 't') {
2520 spec->type = FORMAT_TYPE_PTRDIFF;
2521 } else if (qualifier == 'H') {
2522 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2523 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2524 } else if (qualifier == 'h') {
2525 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2526 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2527 } else {
2528 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2529 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2530 }
2531
2532 return ++fmt - start;
2533 }
2534
2535 static void
set_field_width(struct printf_spec * spec,int width)2536 set_field_width(struct printf_spec *spec, int width)
2537 {
2538 spec->field_width = width;
2539 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2540 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2541 }
2542 }
2543
2544 static void
set_precision(struct printf_spec * spec,int prec)2545 set_precision(struct printf_spec *spec, int prec)
2546 {
2547 spec->precision = prec;
2548 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2549 spec->precision = clamp(prec, 0, PRECISION_MAX);
2550 }
2551 }
2552
2553 /**
2554 * vsnprintf - Format a string and place it in a buffer
2555 * @buf: The buffer to place the result into
2556 * @size: The size of the buffer, including the trailing null space
2557 * @fmt: The format string to use
2558 * @args: Arguments for the format string
2559 *
2560 * This function generally follows C99 vsnprintf, but has some
2561 * extensions and a few limitations:
2562 *
2563 * - ``%n`` is unsupported
2564 * - ``%p*`` is handled by pointer()
2565 *
2566 * See pointer() or Documentation/core-api/printk-formats.rst for more
2567 * extensive description.
2568 *
2569 * **Please update the documentation in both places when making changes**
2570 *
2571 * The return value is the number of characters which would
2572 * be generated for the given input, excluding the trailing
2573 * '\0', as per ISO C99. If you want to have the exact
2574 * number of characters written into @buf as return value
2575 * (not including the trailing '\0'), use vscnprintf(). If the
2576 * return is greater than or equal to @size, the resulting
2577 * string is truncated.
2578 *
2579 * If you're not already dealing with a va_list consider using snprintf().
2580 */
vsnprintf(char * buf,size_t size,const char * fmt,va_list args)2581 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2582 {
2583 unsigned long long num;
2584 char *str, *end;
2585 struct printf_spec spec = {0};
2586
2587 /* Reject out-of-range values early. Large positive sizes are
2588 used for unknown buffer sizes. */
2589 if (WARN_ON_ONCE(size > INT_MAX))
2590 return 0;
2591
2592 str = buf;
2593 end = buf + size;
2594
2595 /* Make sure end is always >= buf */
2596 if (end < buf) {
2597 end = ((void *)-1);
2598 size = end - buf;
2599 }
2600
2601 while (*fmt) {
2602 const char *old_fmt = fmt;
2603 int read = format_decode(fmt, &spec);
2604
2605 fmt += read;
2606
2607 switch (spec.type) {
2608 case FORMAT_TYPE_NONE: {
2609 int copy = read;
2610 if (str < end) {
2611 if (copy > end - str)
2612 copy = end - str;
2613 memcpy(str, old_fmt, copy);
2614 }
2615 str += read;
2616 break;
2617 }
2618
2619 case FORMAT_TYPE_WIDTH:
2620 set_field_width(&spec, va_arg(args, int));
2621 break;
2622
2623 case FORMAT_TYPE_PRECISION:
2624 set_precision(&spec, va_arg(args, int));
2625 break;
2626
2627 case FORMAT_TYPE_CHAR: {
2628 char c;
2629
2630 if (!(spec.flags & LEFT)) {
2631 while (--spec.field_width > 0) {
2632 if (str < end)
2633 *str = ' ';
2634 ++str;
2635
2636 }
2637 }
2638 c = (unsigned char) va_arg(args, int);
2639 if (str < end)
2640 *str = c;
2641 ++str;
2642 while (--spec.field_width > 0) {
2643 if (str < end)
2644 *str = ' ';
2645 ++str;
2646 }
2647 break;
2648 }
2649
2650 case FORMAT_TYPE_STR:
2651 str = string(str, end, va_arg(args, char *), spec);
2652 break;
2653
2654 case FORMAT_TYPE_PTR:
2655 str = pointer(fmt, str, end, va_arg(args, void *),
2656 spec);
2657 while (isalnum(*fmt))
2658 fmt++;
2659 break;
2660
2661 case FORMAT_TYPE_PERCENT_CHAR:
2662 if (str < end)
2663 *str = '%';
2664 ++str;
2665 break;
2666
2667 case FORMAT_TYPE_INVALID:
2668 /*
2669 * Presumably the arguments passed gcc's type
2670 * checking, but there is no safe or sane way
2671 * for us to continue parsing the format and
2672 * fetching from the va_list; the remaining
2673 * specifiers and arguments would be out of
2674 * sync.
2675 */
2676 goto out;
2677
2678 default:
2679 switch (spec.type) {
2680 case FORMAT_TYPE_LONG_LONG:
2681 num = va_arg(args, long long);
2682 break;
2683 case FORMAT_TYPE_ULONG:
2684 num = va_arg(args, unsigned long);
2685 break;
2686 case FORMAT_TYPE_LONG:
2687 num = va_arg(args, long);
2688 break;
2689 case FORMAT_TYPE_SIZE_T:
2690 if (spec.flags & SIGN)
2691 num = va_arg(args, ssize_t);
2692 else
2693 num = va_arg(args, size_t);
2694 break;
2695 case FORMAT_TYPE_PTRDIFF:
2696 num = va_arg(args, ptrdiff_t);
2697 break;
2698 case FORMAT_TYPE_UBYTE:
2699 num = (unsigned char) va_arg(args, int);
2700 break;
2701 case FORMAT_TYPE_BYTE:
2702 num = (signed char) va_arg(args, int);
2703 break;
2704 case FORMAT_TYPE_USHORT:
2705 num = (unsigned short) va_arg(args, int);
2706 break;
2707 case FORMAT_TYPE_SHORT:
2708 num = (short) va_arg(args, int);
2709 break;
2710 case FORMAT_TYPE_INT:
2711 num = (int) va_arg(args, int);
2712 break;
2713 default:
2714 num = va_arg(args, unsigned int);
2715 }
2716
2717 str = number(str, end, num, spec);
2718 }
2719 }
2720
2721 out:
2722 if (size > 0) {
2723 if (str < end)
2724 *str = '\0';
2725 else
2726 end[-1] = '\0';
2727 }
2728
2729 /* the trailing null byte doesn't count towards the total */
2730 return str-buf;
2731
2732 }
2733 EXPORT_SYMBOL(vsnprintf);
2734
2735 /**
2736 * vscnprintf - Format a string and place it in a buffer
2737 * @buf: The buffer to place the result into
2738 * @size: The size of the buffer, including the trailing null space
2739 * @fmt: The format string to use
2740 * @args: Arguments for the format string
2741 *
2742 * The return value is the number of characters which have been written into
2743 * the @buf not including the trailing '\0'. If @size is == 0 the function
2744 * returns 0.
2745 *
2746 * If you're not already dealing with a va_list consider using scnprintf().
2747 *
2748 * See the vsnprintf() documentation for format string extensions over C99.
2749 */
vscnprintf(char * buf,size_t size,const char * fmt,va_list args)2750 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2751 {
2752 int i;
2753
2754 i = vsnprintf(buf, size, fmt, args);
2755
2756 if (likely(i < size))
2757 return i;
2758 if (size != 0)
2759 return size - 1;
2760 return 0;
2761 }
2762 EXPORT_SYMBOL(vscnprintf);
2763
2764 /**
2765 * snprintf - Format a string and place it in a buffer
2766 * @buf: The buffer to place the result into
2767 * @size: The size of the buffer, including the trailing null space
2768 * @fmt: The format string to use
2769 * @...: Arguments for the format string
2770 *
2771 * The return value is the number of characters which would be
2772 * generated for the given input, excluding the trailing null,
2773 * as per ISO C99. If the return is greater than or equal to
2774 * @size, the resulting string is truncated.
2775 *
2776 * See the vsnprintf() documentation for format string extensions over C99.
2777 */
snprintf(char * buf,size_t size,const char * fmt,...)2778 int snprintf(char *buf, size_t size, const char *fmt, ...)
2779 {
2780 va_list args;
2781 int i;
2782
2783 va_start(args, fmt);
2784 i = vsnprintf(buf, size, fmt, args);
2785 va_end(args);
2786
2787 return i;
2788 }
2789 EXPORT_SYMBOL(snprintf);
2790
2791 /**
2792 * scnprintf - Format a string and place it in a buffer
2793 * @buf: The buffer to place the result into
2794 * @size: The size of the buffer, including the trailing null space
2795 * @fmt: The format string to use
2796 * @...: Arguments for the format string
2797 *
2798 * The return value is the number of characters written into @buf not including
2799 * the trailing '\0'. If @size is == 0 the function returns 0.
2800 */
2801
scnprintf(char * buf,size_t size,const char * fmt,...)2802 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2803 {
2804 va_list args;
2805 int i;
2806
2807 va_start(args, fmt);
2808 i = vscnprintf(buf, size, fmt, args);
2809 va_end(args);
2810
2811 return i;
2812 }
2813 EXPORT_SYMBOL(scnprintf);
2814
2815 /**
2816 * vsprintf - Format a string and place it in a buffer
2817 * @buf: The buffer to place the result into
2818 * @fmt: The format string to use
2819 * @args: Arguments for the format string
2820 *
2821 * The function returns the number of characters written
2822 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2823 * buffer overflows.
2824 *
2825 * If you're not already dealing with a va_list consider using sprintf().
2826 *
2827 * See the vsnprintf() documentation for format string extensions over C99.
2828 */
vsprintf(char * buf,const char * fmt,va_list args)2829 int vsprintf(char *buf, const char *fmt, va_list args)
2830 {
2831 return vsnprintf(buf, INT_MAX, fmt, args);
2832 }
2833 EXPORT_SYMBOL(vsprintf);
2834
2835 /**
2836 * sprintf - Format a string and place it in a buffer
2837 * @buf: The buffer to place the result into
2838 * @fmt: The format string to use
2839 * @...: Arguments for the format string
2840 *
2841 * The function returns the number of characters written
2842 * into @buf. Use snprintf() or scnprintf() in order to avoid
2843 * buffer overflows.
2844 *
2845 * See the vsnprintf() documentation for format string extensions over C99.
2846 */
sprintf(char * buf,const char * fmt,...)2847 int sprintf(char *buf, const char *fmt, ...)
2848 {
2849 va_list args;
2850 int i;
2851
2852 va_start(args, fmt);
2853 i = vsnprintf(buf, INT_MAX, fmt, args);
2854 va_end(args);
2855
2856 return i;
2857 }
2858 EXPORT_SYMBOL(sprintf);
2859
2860 #ifdef CONFIG_BINARY_PRINTF
2861 /*
2862 * bprintf service:
2863 * vbin_printf() - VA arguments to binary data
2864 * bstr_printf() - Binary data to text string
2865 */
2866
2867 /**
2868 * vbin_printf - Parse a format string and place args' binary value in a buffer
2869 * @bin_buf: The buffer to place args' binary value
2870 * @size: The size of the buffer(by words(32bits), not characters)
2871 * @fmt: The format string to use
2872 * @args: Arguments for the format string
2873 *
2874 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2875 * is skipped.
2876 *
2877 * The return value is the number of words(32bits) which would be generated for
2878 * the given input.
2879 *
2880 * NOTE:
2881 * If the return value is greater than @size, the resulting bin_buf is NOT
2882 * valid for bstr_printf().
2883 */
vbin_printf(u32 * bin_buf,size_t size,const char * fmt,va_list args)2884 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2885 {
2886 struct printf_spec spec = {0};
2887 char *str, *end;
2888 int width;
2889
2890 str = (char *)bin_buf;
2891 end = (char *)(bin_buf + size);
2892
2893 #define save_arg(type) \
2894 ({ \
2895 unsigned long long value; \
2896 if (sizeof(type) == 8) { \
2897 unsigned long long val8; \
2898 str = PTR_ALIGN(str, sizeof(u32)); \
2899 val8 = va_arg(args, unsigned long long); \
2900 if (str + sizeof(type) <= end) { \
2901 *(u32 *)str = *(u32 *)&val8; \
2902 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
2903 } \
2904 value = val8; \
2905 } else { \
2906 unsigned int val4; \
2907 str = PTR_ALIGN(str, sizeof(type)); \
2908 val4 = va_arg(args, int); \
2909 if (str + sizeof(type) <= end) \
2910 *(typeof(type) *)str = (type)(long)val4; \
2911 value = (unsigned long long)val4; \
2912 } \
2913 str += sizeof(type); \
2914 value; \
2915 })
2916
2917 while (*fmt) {
2918 int read = format_decode(fmt, &spec);
2919
2920 fmt += read;
2921
2922 switch (spec.type) {
2923 case FORMAT_TYPE_NONE:
2924 case FORMAT_TYPE_PERCENT_CHAR:
2925 break;
2926 case FORMAT_TYPE_INVALID:
2927 goto out;
2928
2929 case FORMAT_TYPE_WIDTH:
2930 case FORMAT_TYPE_PRECISION:
2931 width = (int)save_arg(int);
2932 /* Pointers may require the width */
2933 if (*fmt == 'p')
2934 set_field_width(&spec, width);
2935 break;
2936
2937 case FORMAT_TYPE_CHAR:
2938 save_arg(char);
2939 break;
2940
2941 case FORMAT_TYPE_STR: {
2942 const char *save_str = va_arg(args, char *);
2943 const char *err_msg;
2944 size_t len;
2945
2946 err_msg = check_pointer_msg(save_str);
2947 if (err_msg)
2948 save_str = err_msg;
2949
2950 len = strlen(save_str) + 1;
2951 if (str + len < end)
2952 memcpy(str, save_str, len);
2953 str += len;
2954 break;
2955 }
2956
2957 case FORMAT_TYPE_PTR:
2958 /* Dereferenced pointers must be done now */
2959 switch (*fmt) {
2960 /* Dereference of functions is still OK */
2961 case 'S':
2962 case 's':
2963 case 'x':
2964 case 'K':
2965 case 'e':
2966 save_arg(void *);
2967 break;
2968 default:
2969 if (!isalnum(*fmt)) {
2970 save_arg(void *);
2971 break;
2972 }
2973 str = pointer(fmt, str, end, va_arg(args, void *),
2974 spec);
2975 if (str + 1 < end)
2976 *str++ = '\0';
2977 else
2978 end[-1] = '\0'; /* Must be nul terminated */
2979 }
2980 /* skip all alphanumeric pointer suffixes */
2981 while (isalnum(*fmt))
2982 fmt++;
2983 break;
2984
2985 default:
2986 switch (spec.type) {
2987
2988 case FORMAT_TYPE_LONG_LONG:
2989 save_arg(long long);
2990 break;
2991 case FORMAT_TYPE_ULONG:
2992 case FORMAT_TYPE_LONG:
2993 save_arg(unsigned long);
2994 break;
2995 case FORMAT_TYPE_SIZE_T:
2996 save_arg(size_t);
2997 break;
2998 case FORMAT_TYPE_PTRDIFF:
2999 save_arg(ptrdiff_t);
3000 break;
3001 case FORMAT_TYPE_UBYTE:
3002 case FORMAT_TYPE_BYTE:
3003 save_arg(char);
3004 break;
3005 case FORMAT_TYPE_USHORT:
3006 case FORMAT_TYPE_SHORT:
3007 save_arg(short);
3008 break;
3009 default:
3010 save_arg(int);
3011 }
3012 }
3013 }
3014
3015 out:
3016 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
3017 #undef save_arg
3018 }
3019 EXPORT_SYMBOL_GPL(vbin_printf);
3020
3021 /**
3022 * bstr_printf - Format a string from binary arguments and place it in a buffer
3023 * @buf: The buffer to place the result into
3024 * @size: The size of the buffer, including the trailing null space
3025 * @fmt: The format string to use
3026 * @bin_buf: Binary arguments for the format string
3027 *
3028 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3029 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3030 * a binary buffer that generated by vbin_printf.
3031 *
3032 * The format follows C99 vsnprintf, but has some extensions:
3033 * see vsnprintf comment for details.
3034 *
3035 * The return value is the number of characters which would
3036 * be generated for the given input, excluding the trailing
3037 * '\0', as per ISO C99. If you want to have the exact
3038 * number of characters written into @buf as return value
3039 * (not including the trailing '\0'), use vscnprintf(). If the
3040 * return is greater than or equal to @size, the resulting
3041 * string is truncated.
3042 */
bstr_printf(char * buf,size_t size,const char * fmt,const u32 * bin_buf)3043 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
3044 {
3045 struct printf_spec spec = {0};
3046 char *str, *end;
3047 const char *args = (const char *)bin_buf;
3048
3049 if (WARN_ON_ONCE(size > INT_MAX))
3050 return 0;
3051
3052 str = buf;
3053 end = buf + size;
3054
3055 #define get_arg(type) \
3056 ({ \
3057 typeof(type) value; \
3058 if (sizeof(type) == 8) { \
3059 args = PTR_ALIGN(args, sizeof(u32)); \
3060 *(u32 *)&value = *(u32 *)args; \
3061 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3062 } else { \
3063 args = PTR_ALIGN(args, sizeof(type)); \
3064 value = *(typeof(type) *)args; \
3065 } \
3066 args += sizeof(type); \
3067 value; \
3068 })
3069
3070 /* Make sure end is always >= buf */
3071 if (end < buf) {
3072 end = ((void *)-1);
3073 size = end - buf;
3074 }
3075
3076 while (*fmt) {
3077 const char *old_fmt = fmt;
3078 int read = format_decode(fmt, &spec);
3079
3080 fmt += read;
3081
3082 switch (spec.type) {
3083 case FORMAT_TYPE_NONE: {
3084 int copy = read;
3085 if (str < end) {
3086 if (copy > end - str)
3087 copy = end - str;
3088 memcpy(str, old_fmt, copy);
3089 }
3090 str += read;
3091 break;
3092 }
3093
3094 case FORMAT_TYPE_WIDTH:
3095 set_field_width(&spec, get_arg(int));
3096 break;
3097
3098 case FORMAT_TYPE_PRECISION:
3099 set_precision(&spec, get_arg(int));
3100 break;
3101
3102 case FORMAT_TYPE_CHAR: {
3103 char c;
3104
3105 if (!(spec.flags & LEFT)) {
3106 while (--spec.field_width > 0) {
3107 if (str < end)
3108 *str = ' ';
3109 ++str;
3110 }
3111 }
3112 c = (unsigned char) get_arg(char);
3113 if (str < end)
3114 *str = c;
3115 ++str;
3116 while (--spec.field_width > 0) {
3117 if (str < end)
3118 *str = ' ';
3119 ++str;
3120 }
3121 break;
3122 }
3123
3124 case FORMAT_TYPE_STR: {
3125 const char *str_arg = args;
3126 args += strlen(str_arg) + 1;
3127 str = string(str, end, (char *)str_arg, spec);
3128 break;
3129 }
3130
3131 case FORMAT_TYPE_PTR: {
3132 bool process = false;
3133 int copy, len;
3134 /* Non function dereferences were already done */
3135 switch (*fmt) {
3136 case 'S':
3137 case 's':
3138 case 'x':
3139 case 'K':
3140 case 'e':
3141 process = true;
3142 break;
3143 default:
3144 if (!isalnum(*fmt)) {
3145 process = true;
3146 break;
3147 }
3148 /* Pointer dereference was already processed */
3149 if (str < end) {
3150 len = copy = strlen(args);
3151 if (copy > end - str)
3152 copy = end - str;
3153 memcpy(str, args, copy);
3154 str += len;
3155 args += len + 1;
3156 }
3157 }
3158 if (process)
3159 str = pointer(fmt, str, end, get_arg(void *), spec);
3160
3161 while (isalnum(*fmt))
3162 fmt++;
3163 break;
3164 }
3165
3166 case FORMAT_TYPE_PERCENT_CHAR:
3167 if (str < end)
3168 *str = '%';
3169 ++str;
3170 break;
3171
3172 case FORMAT_TYPE_INVALID:
3173 goto out;
3174
3175 default: {
3176 unsigned long long num;
3177
3178 switch (spec.type) {
3179
3180 case FORMAT_TYPE_LONG_LONG:
3181 num = get_arg(long long);
3182 break;
3183 case FORMAT_TYPE_ULONG:
3184 case FORMAT_TYPE_LONG:
3185 num = get_arg(unsigned long);
3186 break;
3187 case FORMAT_TYPE_SIZE_T:
3188 num = get_arg(size_t);
3189 break;
3190 case FORMAT_TYPE_PTRDIFF:
3191 num = get_arg(ptrdiff_t);
3192 break;
3193 case FORMAT_TYPE_UBYTE:
3194 num = get_arg(unsigned char);
3195 break;
3196 case FORMAT_TYPE_BYTE:
3197 num = get_arg(signed char);
3198 break;
3199 case FORMAT_TYPE_USHORT:
3200 num = get_arg(unsigned short);
3201 break;
3202 case FORMAT_TYPE_SHORT:
3203 num = get_arg(short);
3204 break;
3205 case FORMAT_TYPE_UINT:
3206 num = get_arg(unsigned int);
3207 break;
3208 default:
3209 num = get_arg(int);
3210 }
3211
3212 str = number(str, end, num, spec);
3213 } /* default: */
3214 } /* switch(spec.type) */
3215 } /* while(*fmt) */
3216
3217 out:
3218 if (size > 0) {
3219 if (str < end)
3220 *str = '\0';
3221 else
3222 end[-1] = '\0';
3223 }
3224
3225 #undef get_arg
3226
3227 /* the trailing null byte doesn't count towards the total */
3228 return str - buf;
3229 }
3230 EXPORT_SYMBOL_GPL(bstr_printf);
3231
3232 /**
3233 * bprintf - Parse a format string and place args' binary value in a buffer
3234 * @bin_buf: The buffer to place args' binary value
3235 * @size: The size of the buffer(by words(32bits), not characters)
3236 * @fmt: The format string to use
3237 * @...: Arguments for the format string
3238 *
3239 * The function returns the number of words(u32) written
3240 * into @bin_buf.
3241 */
bprintf(u32 * bin_buf,size_t size,const char * fmt,...)3242 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
3243 {
3244 va_list args;
3245 int ret;
3246
3247 va_start(args, fmt);
3248 ret = vbin_printf(bin_buf, size, fmt, args);
3249 va_end(args);
3250
3251 return ret;
3252 }
3253 EXPORT_SYMBOL_GPL(bprintf);
3254
3255 #endif /* CONFIG_BINARY_PRINTF */
3256
3257 /**
3258 * vsscanf - Unformat a buffer into a list of arguments
3259 * @buf: input buffer
3260 * @fmt: format of buffer
3261 * @args: arguments
3262 */
vsscanf(const char * buf,const char * fmt,va_list args)3263 int vsscanf(const char *buf, const char *fmt, va_list args)
3264 {
3265 const char *str = buf;
3266 char *next;
3267 char digit;
3268 int num = 0;
3269 u8 qualifier;
3270 unsigned int base;
3271 union {
3272 long long s;
3273 unsigned long long u;
3274 } val;
3275 s16 field_width;
3276 bool is_sign;
3277
3278 while (*fmt) {
3279 /* skip any white space in format */
3280 /* white space in format matchs any amount of
3281 * white space, including none, in the input.
3282 */
3283 if (isspace(*fmt)) {
3284 fmt = skip_spaces(++fmt);
3285 str = skip_spaces(str);
3286 }
3287
3288 /* anything that is not a conversion must match exactly */
3289 if (*fmt != '%' && *fmt) {
3290 if (*fmt++ != *str++)
3291 break;
3292 continue;
3293 }
3294
3295 if (!*fmt)
3296 break;
3297 ++fmt;
3298
3299 /* skip this conversion.
3300 * advance both strings to next white space
3301 */
3302 if (*fmt == '*') {
3303 if (!*str)
3304 break;
3305 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
3306 /* '%*[' not yet supported, invalid format */
3307 if (*fmt == '[')
3308 return num;
3309 fmt++;
3310 }
3311 while (!isspace(*str) && *str)
3312 str++;
3313 continue;
3314 }
3315
3316 /* get field width */
3317 field_width = -1;
3318 if (isdigit(*fmt)) {
3319 field_width = skip_atoi(&fmt);
3320 if (field_width <= 0)
3321 break;
3322 }
3323
3324 /* get conversion qualifier */
3325 qualifier = -1;
3326 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
3327 *fmt == 'z') {
3328 qualifier = *fmt++;
3329 if (unlikely(qualifier == *fmt)) {
3330 if (qualifier == 'h') {
3331 qualifier = 'H';
3332 fmt++;
3333 } else if (qualifier == 'l') {
3334 qualifier = 'L';
3335 fmt++;
3336 }
3337 }
3338 }
3339
3340 if (!*fmt)
3341 break;
3342
3343 if (*fmt == 'n') {
3344 /* return number of characters read so far */
3345 *va_arg(args, int *) = str - buf;
3346 ++fmt;
3347 continue;
3348 }
3349
3350 if (!*str)
3351 break;
3352
3353 base = 10;
3354 is_sign = false;
3355
3356 switch (*fmt++) {
3357 case 'c':
3358 {
3359 char *s = (char *)va_arg(args, char*);
3360 if (field_width == -1)
3361 field_width = 1;
3362 do {
3363 *s++ = *str++;
3364 } while (--field_width > 0 && *str);
3365 num++;
3366 }
3367 continue;
3368 case 's':
3369 {
3370 char *s = (char *)va_arg(args, char *);
3371 if (field_width == -1)
3372 field_width = SHRT_MAX;
3373 /* first, skip leading white space in buffer */
3374 str = skip_spaces(str);
3375
3376 /* now copy until next white space */
3377 while (*str && !isspace(*str) && field_width--)
3378 *s++ = *str++;
3379 *s = '\0';
3380 num++;
3381 }
3382 continue;
3383 /*
3384 * Warning: This implementation of the '[' conversion specifier
3385 * deviates from its glibc counterpart in the following ways:
3386 * (1) It does NOT support ranges i.e. '-' is NOT a special
3387 * character
3388 * (2) It cannot match the closing bracket ']' itself
3389 * (3) A field width is required
3390 * (4) '%*[' (discard matching input) is currently not supported
3391 *
3392 * Example usage:
3393 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3394 * buf1, buf2, buf3);
3395 * if (ret < 3)
3396 * // etc..
3397 */
3398 case '[':
3399 {
3400 char *s = (char *)va_arg(args, char *);
3401 DECLARE_BITMAP(set, 256) = {0};
3402 unsigned int len = 0;
3403 bool negate = (*fmt == '^');
3404
3405 /* field width is required */
3406 if (field_width == -1)
3407 return num;
3408
3409 if (negate)
3410 ++fmt;
3411
3412 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3413 set_bit((u8)*fmt, set);
3414
3415 /* no ']' or no character set found */
3416 if (!*fmt || !len)
3417 return num;
3418 ++fmt;
3419
3420 if (negate) {
3421 bitmap_complement(set, set, 256);
3422 /* exclude null '\0' byte */
3423 clear_bit(0, set);
3424 }
3425
3426 /* match must be non-empty */
3427 if (!test_bit((u8)*str, set))
3428 return num;
3429
3430 while (test_bit((u8)*str, set) && field_width--)
3431 *s++ = *str++;
3432 *s = '\0';
3433 ++num;
3434 }
3435 continue;
3436 case 'o':
3437 base = 8;
3438 break;
3439 case 'x':
3440 case 'X':
3441 base = 16;
3442 break;
3443 case 'i':
3444 base = 0;
3445 /* fall through */
3446 case 'd':
3447 is_sign = true;
3448 /* fall through */
3449 case 'u':
3450 break;
3451 case '%':
3452 /* looking for '%' in str */
3453 if (*str++ != '%')
3454 return num;
3455 continue;
3456 default:
3457 /* invalid format; stop here */
3458 return num;
3459 }
3460
3461 /* have some sort of integer conversion.
3462 * first, skip white space in buffer.
3463 */
3464 str = skip_spaces(str);
3465
3466 digit = *str;
3467 if (is_sign && digit == '-')
3468 digit = *(str + 1);
3469
3470 if (!digit
3471 || (base == 16 && !isxdigit(digit))
3472 || (base == 10 && !isdigit(digit))
3473 || (base == 8 && (!isdigit(digit) || digit > '7'))
3474 || (base == 0 && !isdigit(digit)))
3475 break;
3476
3477 if (is_sign)
3478 val.s = simple_strntoll(str,
3479 field_width >= 0 ? field_width : INT_MAX,
3480 &next, base);
3481 else
3482 val.u = simple_strntoull(str,
3483 field_width >= 0 ? field_width : INT_MAX,
3484 &next, base);
3485
3486 switch (qualifier) {
3487 case 'H': /* that's 'hh' in format */
3488 if (is_sign)
3489 *va_arg(args, signed char *) = val.s;
3490 else
3491 *va_arg(args, unsigned char *) = val.u;
3492 break;
3493 case 'h':
3494 if (is_sign)
3495 *va_arg(args, short *) = val.s;
3496 else
3497 *va_arg(args, unsigned short *) = val.u;
3498 break;
3499 case 'l':
3500 if (is_sign)
3501 *va_arg(args, long *) = val.s;
3502 else
3503 *va_arg(args, unsigned long *) = val.u;
3504 break;
3505 case 'L':
3506 if (is_sign)
3507 *va_arg(args, long long *) = val.s;
3508 else
3509 *va_arg(args, unsigned long long *) = val.u;
3510 break;
3511 case 'z':
3512 *va_arg(args, size_t *) = val.u;
3513 break;
3514 default:
3515 if (is_sign)
3516 *va_arg(args, int *) = val.s;
3517 else
3518 *va_arg(args, unsigned int *) = val.u;
3519 break;
3520 }
3521 num++;
3522
3523 if (!next)
3524 break;
3525 str = next;
3526 }
3527
3528 return num;
3529 }
3530 EXPORT_SYMBOL(vsscanf);
3531
3532 /**
3533 * sscanf - Unformat a buffer into a list of arguments
3534 * @buf: input buffer
3535 * @fmt: formatting of buffer
3536 * @...: resulting arguments
3537 */
sscanf(const char * buf,const char * fmt,...)3538 int sscanf(const char *buf, const char *fmt, ...)
3539 {
3540 va_list args;
3541 int i;
3542
3543 va_start(args, fmt);
3544 i = vsscanf(buf, fmt, args);
3545 va_end(args);
3546
3547 return i;
3548 }
3549 EXPORT_SYMBOL(sscanf);
3550